On Food And Cooking Part 45

Hypomyces lactifluorum Hypomyces lactifluorum

Fresh truffles are very perishable and emit their aroma in storage. They're best kept refrigerated in a closed container with some material - often rice - to absorb moisture and keep their surface from getting wet and spoiled by microbes.

Huitlacoche, or Corn s.m.u.t Huitlacoche is a parasitic fungus, Ustilago maydis, Ustilago maydis, that attacks corn plants, and that has been eaten in Mexico and Central America since Aztec times. It infects various plant parts, including the kernels in the growing ear, and develops into irregular spongy ma.s.ses or "galls" that are a combination of greatly enlarged plant cells, nutrient-absorbing fungal threads, and blue-black spores. Fully mature galls are dry, black spore bags. The optimum stage for harvest is two to three weeks after infection, when the galls on a single ear can weigh as much as a pound/500 gm and are about three-quarters black inside. When cooked, these immature galls develop a sweet, savory, woody flavor thanks to glucose, sotolon, and vanillin. In the United States, corn s.m.u.t was simply a disease until the 1990s, when growing interest in Mexican food led some farmers to cultivate it intentionally. that attacks corn plants, and that has been eaten in Mexico and Central America since Aztec times. It infects various plant parts, including the kernels in the growing ear, and develops into irregular spongy ma.s.ses or "galls" that are a combination of greatly enlarged plant cells, nutrient-absorbing fungal threads, and blue-black spores. Fully mature galls are dry, black spore bags. The optimum stage for harvest is two to three weeks after infection, when the galls on a single ear can weigh as much as a pound/500 gm and are about three-quarters black inside. When cooked, these immature galls develop a sweet, savory, woody flavor thanks to glucose, sotolon, and vanillin. In the United States, corn s.m.u.t was simply a disease until the 1990s, when growing interest in Mexican food led some farmers to cultivate it intentionally.

A related s.m.u.t, U. esculenta, U. esculenta, is eaten in China and j.a.pan. An Asian wild rice, is eaten in China and j.a.pan. An Asian wild rice, Zizania latifolia, Zizania latifolia, develops the infection in its upper stem, which swells with hyphae. The stems are cooked and eaten as a vegetable (Chinese kah-peh-sung, j.a.panese makomotake) whose flavor is said to resemble bamboo shoots. develops the infection in its upper stem, which swells with hyphae. The stems are cooked and eaten as a vegetable (Chinese kah-peh-sung, j.a.panese makomotake) whose flavor is said to resemble bamboo shoots.

Mycoprotein, or Quorn Mycoprotein is a 20th-century invention, an edible form of the normally useless underground hyphae of a common fungus, Fusarium venenatum. Fusarium venenatum. A strain of the fungus originally taken from a field in Buck-inghams.h.i.+re, England, is grown in a liquid medium in a factory-scale fermenter. The resulting ma.s.s of hyphae is harvested, washed, and rapidly heated. This produces microscopic fibers that are rich in protein and about 0.5 mm long and 0.0030.005 mm in diameter, or about the dimensions of muscle fibers in meat. This essentially tasteless mycoprotein (from A strain of the fungus originally taken from a field in Buck-inghams.h.i.+re, England, is grown in a liquid medium in a factory-scale fermenter. The resulting ma.s.s of hyphae is harvested, washed, and rapidly heated. This produces microscopic fibers that are rich in protein and about 0.5 mm long and 0.0030.005 mm in diameter, or about the dimensions of muscle fibers in meat. This essentially tasteless mycoprotein (from myco-, myco-, "related to fungi") can then be manufactured into meat subst.i.tutes and a variety of other food products. "related to fungi") can then be manufactured into meat subst.i.tutes and a variety of other food products.

Chapter 7.

A Survey of Common Fruits

The Making of Fruit: Ripening Before Ripening: Growth and ExpansionThe Work of Ethylene and EnzymesTwo Styles of Ripening, Two Ways of Handling Common Fruits of Temperate Climates: Apple and Pear, Stone Fruits, Berries Pome Fruits: Apple, Pear, and RelativesStone Fruits: Apricot, Cherry, Peach, and PlumBerries, Including Grapes and Kiwi FruitOther Temperate Fruits Fruits from Warm Climates: Melons, Citrus Fruits, Tropical Fruits, and Others MelonsFruits from Arid Climates: Fig, Date, and OthersThe Citrus Family: Orange, Lemon, Grapefruit, and RelativesSome Common Tropical Fruits The vegetables described in chapter 6 are mainly plant parts with either mild, accidental flavors (roots, leaves, stalks) or strong defensive ones (the onion and cabbage families). We usually cook them, because cooking improves their flavor and makes them softer and easier to eat. The fruits described in this chapter are parts that the plant creates in order to attract animals to eat them and disperse the seeds within them. So the plant fills these fruits with a mouthwatering mixture of sugars and acids, endows them with pleasant aromas and eye-catching colors, and softens them for us: they're delicious and beautiful even when raw. The box on pp. 382383 summarizes the essential flavor elements of some common fruits, especially the balance between sweet and sour that provides their taste foundation.

The Making of Fruit: Ripening Among all our foods, fruits are unique in the way that they progress from inedibility to deliciousness. Immature vegetables and young meat animals are at their tenderest and most delicate, but immature fruits are usually at their least appealing. We may still eat and enjoy them - green tomatoes, green papayas, green mangoes - but we treat them as vegetables, cut them small for a salad or cook or pickle them. In order to graduate from vegetablehood, fruits must undergo the process called ripening, which creates their distinctive character.

Before Ripening: Growth And Expansion A fruit is a distinct organ that develops from the flower, and in particular from the flower's female tissue, the ovary, which encloses the plant's maturing seeds. Most fruits are simply the thickened ovary wall, or else they incorporate nearby tissues as well. Apples and pears, for example, are made up mainly of the stem tip in which the flower parts are embedded. The fruit usually develops into three distinct layers: a thin outer protective skin, a thin inner protective coat around the central ma.s.s of seeds, and a thick, succulent, flavorful layer in between.

Fruit goes through four distinct stages of development. The first is usually fertilization of the female ovule by male pollen, which initiates the production of growth-promoting hormones and so leads to the expansion of the flower's ovary wall. Some conveniently seedless fruits, including bananas, navel oranges, and some grapes, manage to develop without fertilization. The second, relatively brief stage of fruit development is the multiplication of cells in the ovary wall, which in the tomato is virtually complete at the moment of fertilization (you can see the fully formed but tiny fruit at the base of the flower as soon as it opens).

Most of the noticeable growth during fruit development takes place during the third stage, the expansion of the storage cells. This growth can be remarkable. Melons at their most active put on better than 5 cubic inches/80 cc a day. Most of this expansion is due to the acc.u.mulation of water-based sap in the cell vacuoles. Mature fruit storage cells are among the largest in the plant kingdom, in watermelons approaching a millimeter in diameter. During this growth stage, sugar is stored in the cell vacuole as is or in more compact granules of starch. Defensive compounds, among them poisonous alkaloids and astringent tannins, acc.u.mulate in the cell vacuoles to deter infection or predation, and various enzyme systems are readied for action. When the seeds become capable of growing on their own and the fruit is ready to attract animals to disperse them, the fruit is said to be mature.

The Work of Ethylene and Enzymes The final stage of fruit development is ripening, a drastic change in the life of the fruit that leads to its death. It consists of several simultaneous events. Starch and acid levels decrease, and sugars increase. The texture softens; defensive compounds disappear. A characteristic aroma develops. Skin color changes, usually from green to a shade of yellow or red. The fruit thus becomes sweeter, softer, and tastier, and it advertises these improvements visually. Because ripening soon gives way to rot-ting, ripening was long considered to be an early stage in the fruit's general disintegration. But it's now clear that ripening is a last, intense phase of life. As it ripens, the fruit actively prepares for its end, organizing itself into a feast for our eye and palate.

Food Words: Ripe, Climacteric Ripe, ClimactericOur word ripe ripe began as an Old English word meaning "ready for reaping," and like began as an Old English word meaning "ready for reaping," and like reap reap comes ultimately from an Indo-European root meaning "to cut." comes ultimately from an Indo-European root meaning "to cut." River, rope, row, River, rope, row, and and rigatoni rigatoni are all relatives. are all relatives. Climacteric Climacteric can be traced back to a root meaning "to lean," which led to the Greek can be traced back to a root meaning "to lean," which led to the Greek climax, climax, "ladder," then offshoots meaning "rung" and therefore "a dangerous place," and finally "ladder," then offshoots meaning "rung" and therefore "a dangerous place," and finally climacteric climacteric itself, meaning a critical stage in life - whether a human's or a fruit's. itself, meaning a critical stage in life - whether a human's or a fruit's.

Fruits: Their Potential for Improvement after Harvest, and Optimal Storage Temperatures Most of the changes in ripening are caused by a host of enzymes, which break down complex molecules into simpler ones, and also generate new molecules just for this moment in the fruit's life. There is a single trigger that sets the ripening enzymes into action. The first clues to its ident.i.ty came around 1910. From the Caribbean islands came a report that bananas stored near some oranges had ripened earlier than the other bunches. Then California citrus growers noticed that green fruit kept near a kerosene stove changed color faster than the rest. What secret ripening agent did stove and fruit have in common? The answer came two decades later: ethylene, a simple hydrocarbon gas produced by both plants and kerosene combustion, which triggers ripening in mature but unripe fruit. Much later, scientists found that fruits themselves produce ethylene well in advance of ripening. It is thus a hormone that initiates this process in an organized way.

Two Styles of Ripening, Two Ways of Handling There are two different styles of ripening among fruits. One is dramatic. When triggered by ethylene, the fruit stimulates itself by producing more ethylene, and begins to respire respire - to use up oxygen and produce carbon dioxide - from two to five times faster than before. Its flavor, texture, and color change rapidly, and afterwards they often decline rapidly as well. Such "climacteric" fruits can be harvested while mature but still green, and will ripen well on their own, especially if nudged by an artificial dose of ethylene. They often store their sugars in the form of starch, which enzymes convert back into sweetness during the post-harvest ripening. - to use up oxygen and produce carbon dioxide - from two to five times faster than before. Its flavor, texture, and color change rapidly, and afterwards they often decline rapidly as well. Such "climacteric" fruits can be harvested while mature but still green, and will ripen well on their own, especially if nudged by an artificial dose of ethylene. They often store their sugars in the form of starch, which enzymes convert back into sweetness during the post-harvest ripening.

The other style of ripening is undramatic. "Nonclimacteric" fruits don't respond to ethylene with their own escalating ethylene production. They ripen gradually, usually don't store sugars as starch, and so depend on their connection to the parent plant for continued sweetening. Once harvested, they get no sweeter, though other enzyme actions may continue to soften cell walls and generate aroma molecules.

These basic styles of ripening determine how fruits are handled in commerce and in the kitchen. Climacteric fruits like bananas and avocados, pears and tomatoes can be picked mature but still hard to minimize physical damage, packed and s.h.i.+pped to their destinations, then ga.s.sed with ethylene to ripen them for the produce bin. Consumers can hasten the process by enclosing the fruits in a paper bag with a ripe fruit (plastic traps too much moisture) to expose them to an active ethylene emitter and concentrate the ethylene gas in the air around them. Nonclimacteric fruits like pineapples, citrus fruits, most berries, and melons don't store starch or improve markedly after harvest, so their quality depends mainly on how far they had ripened on the plant. They're best when picked and s.h.i.+pped as ripe as possible, and there's nothing consumers can do to influence their quality: we simply have to choose good ones in the first place.

With just a few exceptions (pears, avocados, kiwis, bananas), even climacteric fruits will be much better if they're allowed to ripen on the plant, from which they can continue to acc.u.mulate the raw materials of flavor until the harvest.

Common Fruits of Temperate Climates: Apple and Pear, Stone Fruits, Berries Pome Fruits: Apple, Pear, and Relatives Apples, pears, and quinces are closely related members of the rose family, natives of Eurasia that were domesticated in prehistoric times. They are a kind of fruit known as a pome pome (from the Latin for "fruit"). The fleshy portion of a pome fruit is the greatly enlarged tip of the flower stem. The remains of the flower project from the bottom of the fruit, and the few small seeds are protected in a tough-walled core. Apples and their relatives are climacteric fruit, and contain starch stores that can be turned into sugar after harvest. They generally keep well in cold storage, though late-harvested fruit tend to develop brown cores. Apples are generally sold ripe and keep best if immediately wrapped and refrigerated; pears are sold unripe and are best ripened at relatively cool room temperatures, then refrigerated without close wrapping. (from the Latin for "fruit"). The fleshy portion of a pome fruit is the greatly enlarged tip of the flower stem. The remains of the flower project from the bottom of the fruit, and the few small seeds are protected in a tough-walled core. Apples and their relatives are climacteric fruit, and contain starch stores that can be turned into sugar after harvest. They generally keep well in cold storage, though late-harvested fruit tend to develop brown cores. Apples are generally sold ripe and keep best if immediately wrapped and refrigerated; pears are sold unripe and are best ripened at relatively cool room temperatures, then refrigerated without close wrapping.

The reddish colors of pome fruits (usually in the skin but sometimes in the flesh) are due mainly to water-soluble anthocyanin pigments, their yellow and cream colors to fat-soluble carotenoids, including beta-carotene and lutein (pp. 257, 267). These fruits are good sources of phenolic antioxidant compounds (p. 267), particularly simple ones (chlorogenic acid, also found in coffee), which are especially concentrated in the skin. Some apples have an antioxidant activity equivalent to the vitamin C in 30 equal portions of orange!

Apples and pears owe their primary flavors to characteristic esters (see box, p. 355). The flavors of pome fruits differ among varieties, among fruits on different parts of a single tree, and even within a single fruit, from top to bottom and from the core outwards. Pears are often noticeably more flavorful at the flower end than at the stem end. Both apples and pears contain an indigestible, slightly sweet sugar alcohol, sorbitol (0.5%), so a large helping of cider can cause the same discomfort as do inulin-rich foods (p. 307).

Apples Apple trees are especially hardy and are probably the most widely distributed fruit trees on the planet. There are 35 species in the genus Apple trees are especially hardy and are probably the most widely distributed fruit trees on the planet. There are 35 species in the genus Malus. Malus. The species that gives us most of our eating apples, The species that gives us most of our eating apples, Malus Malus x x domestica, domestica, seems to have originated in the mountains of Kazakhstan from crossings of an Asian species ( seems to have originated in the mountains of Kazakhstan from crossings of an Asian species (Malus sieversii) with several cousins. The domesticated apple spread very early through the Middle East. It was known in the Mediterranean region by the time of the Greek epics, and the Romans introduced it to the rest of Europe. These days apple production is an international enterprise, with southern hemisphere countries supplementing northern stored apples during the off-season, and common varieties as likely to have come from Asia (e.g., Fuji, from j.a.pan) as from the West. There are several thousand named apple varieties, which can be divided into four general groups.

Pome fruits and the flower from which they arise. The edible portion of apples and pears derives from the flower base, or receptacle. Because the ovary is set below most of the flower parts, the flower remains a scar at the bottom of the fruit.

Cider apples (mainly the European native (mainly the European native Malus sylvestris Malus sylvestris) are high-acid fruits rich in astringent tannins, qualities that help control the alcoholic fermentation and clarify the liquid (tannins cross-link protein and cell-wall particles and cause them to precipitate). They're used only in cider making.

Dessert or eating apples are crisp and juicy, and have a pleasing balance between sour and sweet when eaten raw (pH 3.4, 15% sugar), but become relatively bland when cooked. Most of the apples in supermarkets and produce markets are dessert apples. are crisp and juicy, and have a pleasing balance between sour and sweet when eaten raw (pH 3.4, 15% sugar), but become relatively bland when cooked. Most of the apples in supermarkets and produce markets are dessert apples.

Cooking apples are distinctly tart when raw (a pH around 3 and sugar content around 12%), well-balanced when cooked, and have a firm flesh that tends to maintain its structure when heated in pies or tarts, rather than falling immediately into a puree or - as in some early "codling" varieties - into a fluffy froth. Many countries have traditionally had their standard cooking apples (France its are distinctly tart when raw (a pH around 3 and sugar content around 12%), well-balanced when cooked, and have a firm flesh that tends to maintain its structure when heated in pies or tarts, rather than falling immediately into a puree or - as in some early "codling" varieties - into a fluffy froth. Many countries have traditionally had their standard cooking apples (France its Calville blanc d'hiver, Calville blanc d'hiver, England its Bramley's Seedling, Germany its England its Bramley's Seedling, Germany its Glockenapfel Glockenapfel for strudel). But these are being replaced by dual-purpose varieties. for strudel). But these are being replaced by dual-purpose varieties.

Dual-purpose apples are adequate either raw or cooked (e.g., Golden Delicious, Granny Smith). These are usually at their best for cooking when young and tart, best for eating when older and more mellow. are adequate either raw or cooked (e.g., Golden Delicious, Granny Smith). These are usually at their best for cooking when young and tart, best for eating when older and more mellow.

An apple's potential for cooking can be tested by wrapping a few slices in aluminum foil and baking in a hot oven for 15 minutes, or microwaving a few slices wrapped in plastic film until the film balloons with steam.

Apple Flavor Apple varieties can have very distinctive flavors, and these evolve even after the fruit are picked from the tree. The English were great connoisseurs a century ago, and Edward Bunyard wrote that by storing apples properly in a cool place and tasting them periodically, the apple lover could "catch the volatile ethers at their maximum development, and the acids and sugars at their most grateful balance." Apples do become more mellow with time because they consume some of their malic acid for energy. Much of their aroma comes from the skin, where volatile-creating enzymes are concentrated. The distinctive aroma of cooked apple pulp comes largely from a floral-smelling fragment of the carotenoid pigments (damascenone). Apple varieties can have very distinctive flavors, and these evolve even after the fruit are picked from the tree. The English were great connoisseurs a century ago, and Edward Bunyard wrote that by storing apples properly in a cool place and tasting them periodically, the apple lover could "catch the volatile ethers at their maximum development, and the acids and sugars at their most grateful balance." Apples do become more mellow with time because they consume some of their malic acid for energy. Much of their aroma comes from the skin, where volatile-creating enzymes are concentrated. The distinctive aroma of cooked apple pulp comes largely from a floral-smelling fragment of the carotenoid pigments (damascenone).

Fruit Aroma Compounds: EstersMany fruits owe their characteristic aroma to chemicals called esters. esters. An ester molecule is a combination of two other molecules, an acid and an alcohol. A typical plant cell contains many different kinds of acids, and several different kinds of alcohol. The acids may be either tart substances in the cell fluids or vacuole - acetic acid, cinnamic acid - or fatty-acid portions of oil molecules and the molecules that make up cell membranes: hexanoic acid, butyric acid. The alcohols are usually by-products of cell metabolism. Fruits have enzymes that join these basic cell materials into aromatic esters. A single fruit will emit many esters, but one or two account for most of its characteristic aroma. Some examples: An ester molecule is a combination of two other molecules, an acid and an alcohol. A typical plant cell contains many different kinds of acids, and several different kinds of alcohol. The acids may be either tart substances in the cell fluids or vacuole - acetic acid, cinnamic acid - or fatty-acid portions of oil molecules and the molecules that make up cell membranes: hexanoic acid, butyric acid. The alcohols are usually by-products of cell metabolism. Fruits have enzymes that join these basic cell materials into aromatic esters. A single fruit will emit many esters, but one or two account for most of its characteristic aroma. Some examples:ethyl alcohol + acetic acid = ethyl acetate, a characteristic note in appleshexyl alcohol + acetic acid = hexyl acetate in pea.r.s.ethyl alcohol + butyric acid = ethyl butyrate in pineappleisoamyl alcohol + acetic acid = isoamyl acetate in bananas Apple Air and Texture Apples differ from pears in having as much as a quarter of their volume occupied by air, thanks to open s.p.a.ces between cells in the fruit. (Pears are less than 5% air.) The air s.p.a.ces contribute to the typical mealiness of an overripe apple: as the cell walls soften and the cell interiors dry out, biting into the apple simply pushes the largely separated cells apart from each other rather than breaking the cells and releasing pent-up juices. Air cells become a factor in baking whole apples; they fill with steam and expand as the apple cooks, and the skin will split unless a strip is removed from the top to release the pressure. Apples differ from pears in having as much as a quarter of their volume occupied by air, thanks to open s.p.a.ces between cells in the fruit. (Pears are less than 5% air.) The air s.p.a.ces contribute to the typical mealiness of an overripe apple: as the cell walls soften and the cell interiors dry out, biting into the apple simply pushes the largely separated cells apart from each other rather than breaking the cells and releasing pent-up juices. Air cells become a factor in baking whole apples; they fill with steam and expand as the apple cooks, and the skin will split unless a strip is removed from the top to release the pressure.

Both apples and crabapples are good sources of cell-wall pectins (p. 265) and make excellent jellies. For the same reason, a simple puree of apples has a thick, satisfying consistency when briefly cooked into apple-sauce, or slowly reduced to "apple b.u.t.ter."

Apple Juice and Cider Apple juice can be either opalescent or clear depending on whether its pectins and proteins are left intact to deflect light rays. Made fresh, it will stay pale and retain its fresh flavor for about an hour, after which the darkening and aroma-modifying influences of enzymes and oxygen become evident. Browning can be minimized by heating the juice rapidly to the boil to inactivate the browning enzymes, but of course this lends a cooked flavor to the juice. Pasteurized apple juice was first manufactured around 1900 in Switzerland, and is now one of the most important commercial fruit products in the United States. Cider is still an important product in northwest Spain, western France, and England, where the traditional method was to let the fruit pulp ferment slowly through the cold winter, reaching an alcohol content around 4%. Apple juice can be either opalescent or clear depending on whether its pectins and proteins are left intact to deflect light rays. Made fresh, it will stay pale and retain its fresh flavor for about an hour, after which the darkening and aroma-modifying influences of enzymes and oxygen become evident. Browning can be minimized by heating the juice rapidly to the boil to inactivate the browning enzymes, but of course this lends a cooked flavor to the juice. Pasteurized apple juice was first manufactured around 1900 in Switzerland, and is now one of the most important commercial fruit products in the United States. Cider is still an important product in northwest Spain, western France, and England, where the traditional method was to let the fruit pulp ferment slowly through the cold winter, reaching an alcohol content around 4%.

Pears Pears are fruit of the genus Pears are fruit of the genus Pyrus, Pyrus, more temperamental to grow than the apple and less common, but called by some "the queen of fruit" for their refinement of flavor, texture, and shape. Pears are less tart than apples, and denser. The familiar elongated European pears, with mostly smooth flesh, are varieties of the west Asian more temperamental to grow than the apple and less common, but called by some "the queen of fruit" for their refinement of flavor, texture, and shape. Pears are less tart than apples, and denser. The familiar elongated European pears, with mostly smooth flesh, are varieties of the west Asian Pyrus communis. Pyrus communis. "Asian pears" are varieties of two species native to China but intensively improved in j.a.pan, "Asian pears" are varieties of two species native to China but intensively improved in j.a.pan, P. pyrifolia P. pyrifolia and and P. ussuriensis. P. ussuriensis. They have a juicy but crisp flesh, more or less gritty with cellulose-rich "stone cells," and may be elongated or apple-shaped. The characteristic aroma of pears comes from several esters, including the "pear ester" (ethyl decadienoate). They have a juicy but crisp flesh, more or less gritty with cellulose-rich "stone cells," and may be elongated or apple-shaped. The characteristic aroma of pears comes from several esters, including the "pear ester" (ethyl decadienoate).

Some Distinctive Apple Flavors and Varieties

Flavor

Varieties Varieties

Simple, refres.h.i.+ng

Gravenstein, Granny Smith Gravenstein, Granny Smith

Strawberry, raspberry

Northern Spy, Spitzenburg Northern Spy, Spitzenburg

Winey

McIntosh (well matured) McIntosh (well matured)

Aromatic and flowery

c.o.x's Orange and Ribston Pippins c.o.x's Orange and Ribston Pippins

Honey

Golden Delicious (well matured), Fuji, Gala Golden Delicious (well matured), Fuji, Gala

Anise or tarragon

Ellison's Orange, Fenouillet Ellison's Orange, Fenouillet

Pineapple

Newtown Pippin, Ananas Reinette Newtown Pippin, Ananas Reinette

Banana

Dodds Dodds

Nutty

Blenheim Orange Blenheim Orange

Nutmeg

D'Arcy Spice D'Arcy Spice

In general, pears have a higher respiratory rate than apples and don't store as well. They're unique among temperate fruits in being of the highest quality when picked mature but still hard and ripened off the tree; picked after ripening begins, their texture becomes mushy and their core breaks down. They will also develop a mealy core if excessively warmed after cold storage. They're best ripened slowly over several days at between 6568F/1820C. Pears are sensitive to carbon dioxide, so they shouldn't be enclosed in plastic bags at any stage. Asian pears are especially p.r.o.ne to bruising and are often marketed in protective sleeves.

Pear Varieties Originally, all pears were gritty "sand pears" and hard-fleshed. Centuries of breeding greatly reduced the prominence of gritty stone cells (but not in varieties for making perry, the pear version of cider, where they're valued for helping to grind the flesh before fermentation). The soft "b.u.t.ter" texture characteristic of many European pears was developed in the 18th century by Belgian and French breeders. European pears are cla.s.sified in three groups according to when they're harvested and their traditional storage life (now extended by controlled atmospheres and temperatures). Summer pears like the Bartlett (also called Williams or Bon chretien) are harvested in July and August and keep for one to three months; autumn pears like the Bosc and Comice are harvested in September and October and keep two to four months; and winter pears like the Anjou and Winter Nellis are harvested in October and November and keep six to seven months. Originally, all pears were gritty "sand pears" and hard-fleshed. Centuries of breeding greatly reduced the prominence of gritty stone cells (but not in varieties for making perry, the pear version of cider, where they're valued for helping to grind the flesh before fermentation). The soft "b.u.t.ter" texture characteristic of many European pears was developed in the 18th century by Belgian and French breeders. European pears are cla.s.sified in three groups according to when they're harvested and their traditional storage life (now extended by controlled atmospheres and temperatures). Summer pears like the Bartlett (also called Williams or Bon chretien) are harvested in July and August and keep for one to three months; autumn pears like the Bosc and Comice are harvested in September and October and keep two to four months; and winter pears like the Anjou and Winter Nellis are harvested in October and November and keep six to seven months.

Quince Quinces, fruit of the central Asian tree Quinces, fruit of the central Asian tree Cydonia oblonga, Cydonia oblonga, give us a taste of what apples and pears might have been like in their primitive form. They are gritty with stone cells, astringent, and hard even when ripe. But they have a distinctive, flowery aroma (thanks to lactones and violet-like ionones, all derived from carotenoid molecules) that's especially concentrated in the fuzzy yellow skin. And cooking domesticates them: heat breaks down and softens their pectin-rich cell walls, and the astringent tannins become bound up in the debris, so the taste softens as well. Quince paste firm enough to slice is a traditional product of Spain ( give us a taste of what apples and pears might have been like in their primitive form. They are gritty with stone cells, astringent, and hard even when ripe. But they have a distinctive, flowery aroma (thanks to lactones and violet-like ionones, all derived from carotenoid molecules) that's especially concentrated in the fuzzy yellow skin. And cooking domesticates them: heat breaks down and softens their pectin-rich cell walls, and the astringent tannins become bound up in the debris, so the taste softens as well. Quince paste firm enough to slice is a traditional product of Spain (membrillo) and Italy (cotognata), and in Portugal a quince preserve was the original marmalade (marmalada). The 16th-century alchemist and confectioner Nostradamus gave several recipes for quince preserves and observed that cooks "who peel them [before cooking] don't know why they do this, for the skin augments the odor." (The same is true for apples.) Quinces have another enchanting quality: when slices are slowly cooked in sugar over several hours, they turn from a pale off-white to pink to a translucent, deep ruby red. The key to this transformation is the fruit's store of colorless phenolic compounds, some of which cooking turns into anthocyanin pigments (p. 281). Pears contain the same compounds, but in smaller quant.i.ties (common Bartletts about a twenty-fifth, Packhams a tenth to a half), and so usually get pink at best.

Medlar Medlars are small fruits of an apple relative ( Medlars are small fruits of an apple relative (Mespilus germanica) native to central Asia, now rare but once commonly grown in Europe as a winter fruit. Like the quince, the medlar remains hard and astringent even when ripe, so it keeps well and even improves if left on the tree through early frosts. It was made into preserves, but more often it was "bletted" (a 19th-century coinage from the French blesse, blesse, "bruised"), or picked from the tree and kept in a cool, dry place for several weeks until the enzymes in its own cells digest it from within, and its flesh turns soft and brown. The astringency disappears, the malic acid is used up, and the aroma develops strong overtones of spice, baked apples, wine, and gentle decay, what D. H. Lawrence described as an "exquisite odour of leave-taking." "bruised"), or picked from the tree and kept in a cool, dry place for several weeks until the enzymes in its own cells digest it from within, and its flesh turns soft and brown. The astringency disappears, the malic acid is used up, and the aroma develops strong overtones of spice, baked apples, wine, and gentle decay, what D. H. Lawrence described as an "exquisite odour of leave-taking."

Loquat Loquats bear little resemblance to their cousin pomes. They are small, elongated fruits of a Chinese tree, Loquats bear little resemblance to their cousin pomes. They are small, elongated fruits of a Chinese tree, Eriobotrya j.a.ponica, Eriobotrya j.a.ponica, which was greatly improved by the j.a.panese and taken to many subtropical regions in the 19th century, notably Sicily, where they are called which was greatly improved by the j.a.panese and taken to many subtropical regions in the 19th century, notably Sicily, where they are called nespole. nespole. They usually ripen early, before cherries. They have a mild, delicate flavor and a wall of carotenoid-containing flesh that runs from white to orange, surrounding several large seeds. U.S. varieties are mainly ornamental and produce small fruit, while European and Asian fruits may approach a half pound/250 gm. They're eaten fresh, made into jellies and jams, and cooked in a spicy syrup in the manner of "pickled" peaches. Loquats are neither climacteric nor chill-sensitive, and so keep well. They usually ripen early, before cherries. They have a mild, delicate flavor and a wall of carotenoid-containing flesh that runs from white to orange, surrounding several large seeds. U.S. varieties are mainly ornamental and produce small fruit, while European and Asian fruits may approach a half pound/250 gm. They're eaten fresh, made into jellies and jams, and cooked in a spicy syrup in the manner of "pickled" peaches. Loquats are neither climacteric nor chill-sensitive, and so keep well.

Stone Fruits: Apricot, Cherry, Peach, and Plum Stone fruits are all species of the genus Prunus, Prunus, members of the large rose family and relatives of the pome fruits. They owe their name to the stone-hard "sh.e.l.l" that surrounds a single large seed at their center. Though the 15 species of members of the large rose family and relatives of the pome fruits. They owe their name to the stone-hard "sh.e.l.l" that surrounds a single large seed at their center. Though the 15 species of Prunus Prunus are found throughout the northern hemisphere, the important stone fruits mostly come from Asia. They do not store starch and so get no sweeter after harvest, though they do soften and develop aroma. Their internal tissues tend to become mealy or break down in prolonged cold storage, so fresh stone fruits are more seasonal than hardier apples and pears. Like some of the pome fruits, stone fruits acc.u.mulate the indigestible sugar alcohol sorbitol (a frequent ingredient in sugar-free gums and candies, p. 662); they're also rich in antioxidant phenolic compounds. The seeds of stone fruits are protected by a cyanide-generating enzyme that also produces the characteristic aroma of almond extract (almonds are seeds of are found throughout the northern hemisphere, the important stone fruits mostly come from Asia. They do not store starch and so get no sweeter after harvest, though they do soften and develop aroma. Their internal tissues tend to become mealy or break down in prolonged cold storage, so fresh stone fruits are more seasonal than hardier apples and pears. Like some of the pome fruits, stone fruits acc.u.mulate the indigestible sugar alcohol sorbitol (a frequent ingredient in sugar-free gums and candies, p. 662); they're also rich in antioxidant phenolic compounds. The seeds of stone fruits are protected by a cyanide-generating enzyme that also produces the characteristic aroma of almond extract (almonds are seeds of Prunus amygdalus). They thus lend an almond character when included in sugar and alcohol preserves, and can replace "bitter almonds" in European pastries and sweets (p. 506).

Apricot The apricots that are most familiar in the West are fruits of The apricots that are most familiar in the West are fruits of Prunus armeniaca, Prunus armeniaca, a native of China that was taken to the Mediterranean during Roman times. There are now thousands of different varieties, white and red (from lycopene) as well as orange, and most of them adapted to specific climates; apricots flower and fruit early (the name comes from the Latin a native of China that was taken to the Mediterranean during Roman times. There are now thousands of different varieties, white and red (from lycopene) as well as orange, and most of them adapted to specific climates; apricots flower and fruit early (the name comes from the Latin praec.o.x, praec.o.x, "precocious"), and therefore bear best in areas with mild, predictable winters. Several other species are grown in Asia, including "precocious"), and therefore bear best in areas with mild, predictable winters. Several other species are grown in Asia, including P. mume, P. mume, whose fruits the j.a.panese salt-pickle and color red to make the condiment whose fruits the j.a.panese salt-pickle and color red to make the condiment umebos.h.i.+. umebos.h.i.+. The distinctive aroma of fresh apricots comes from a rich mixture of terpenes that provide citrus, herbal, and floral notes, and from peach-like compounds (lactones). They are rich in pectin, which gives them a luscious texture when fully ripe, a meaty texture when dried. The distinctive aroma of fresh apricots comes from a rich mixture of terpenes that provide citrus, herbal, and floral notes, and from peach-like compounds (lactones). They are rich in pectin, which gives them a luscious texture when fully ripe, a meaty texture when dried.

Stone fruits and the flower from which they arise. Peaches and cherries derive from an ovary that sits above the base of the flower parts, so the fruits show no remnants of the flower.

Apricots are delicate fruits that don't travel well, so most are processed. They're especially suited to drying, which concentrates their sweet-tart flavor well even when they're overripe. Most dried apricots in the United States come either from a few western states or from Turkey, which exports a relatively pale, bland variety with half the carotenoid pigments and acidity of the Blenheim and Patterson varieties of California. The fruits are dried in the sun in early summer for one or two weeks, until they reach a moisture content of 1520%. Usually they're treated with sulfur dioxide to preserve the abundant beta-carotene and other carotenoids, vitamin C, and fresh flavor. Unsulfured apricots are brown and have a flatter, cooked taste.

Cherry Cherries come in two basic types from two different species, both of which are native to western Asia and southeast Europe. Sweet cherries are the fruits of Cherries come in two basic types from two different species, both of which are native to western Asia and southeast Europe. Sweet cherries are the fruits of Prunus avium, Prunus avium, which is probably one of the parents of the sour cherry, which is probably one of the parents of the sour cherry, Prunus cerasus. Prunus cerasus. Sweet and sour cherries differ mainly in their maximum sugar content, with sweet cherries acc.u.mulating significantly more. Cherries don't improve once they're harvested, so they must be picked ripe and fragile. Most sweet cherries grown in the United States are sold fresh, but far more sour cherries are grown, and most of these are processed. Cherries are prized not only for their flavor, but for their color, which may range from very deep red (rich in anthocyanins) to a pale yellow. The red varieties are an excellent source of phenolic antioxidants. Sweet and sour cherries differ mainly in their maximum sugar content, with sweet cherries acc.u.mulating significantly more. Cherries don't improve once they're harvested, so they must be picked ripe and fragile. Most sweet cherries grown in the United States are sold fresh, but far more sour cherries are grown, and most of these are processed. Cherries are prized not only for their flavor, but for their color, which may range from very deep red (rich in anthocyanins) to a pale yellow. The red varieties are an excellent source of phenolic antioxidants.

Cherry flavor comes mainly from almondy benzaldehyde, a flowery terpene (linalool), and essence of clove (eugenol). Heating increases both the almond and flowery notes, especially if the pits are left in the fruit. This is why the cla.s.sic French cherry clafoutis, a custardy tart, is intensely flavored but requires care in eating!

The familiar "maraschino" cherry originated several centuries ago in northeastern Italy and the neighboring Balkans, where the local marasca cherry was preserved in its own liqueur for winter eating. In the modern industrial version, light-fleshed varieties are bleached with sulfur dioxide and stored in brine until needed, then infused with sugar syrup, dyed cherry red, flavored with almond extract, and pasteurized. After all that, what's left of the original cherry is mainly its skeleton, the cell walls and skin.

Peach and Nectarine Peaches and nectarines are both fruits of the species Peaches and nectarines are both fruits of the species Prunus persica. Prunus persica. Nectarines are varieties with a smooth skin that are usually also smaller, firmer, and more aromatic than their fuzzy siblings. The words "peach" and "persica" come from "Persia," by way of which the fruit reached the Mediterranean world from China by about 300 Nectarines are varieties with a smooth skin that are usually also smaller, firmer, and more aromatic than their fuzzy siblings. The words "peach" and "persica" come from "Persia," by way of which the fruit reached the Mediterranean world from China by about 300 BCE BCE.