HM 176 Ch 14: Fruits

A fruit juice beverage that contains not less than 30 to 40% fruit juice would be classified as a(n)

nectar

As a fruit changes from immature to over ripe, protopectin chemically breaks down to:

pectin then to pectic acid

Apples and pears, with their seeds contained in a central core are called

pomes

Jams are best described as fruit preserves made from

Ground or mashed whole cook fruit

Storage of fruits

-Most ripe fruit should be stored in the refrigerator in plastic bags punctured with air holes -bananas, which will turn brown if refrigerated are the exception. -Unripe fruit is usually left at room temperature in a paper bag and until ripe

Certain fruits turn brown when cut open and exposed to air. Describe the process by which this occurs. What steps can be taken to inhibit browning?

-Phenolic compounds found in fruits are responsible for the browning and bruising that often occur in ripening fruit -includes apples, apricots, avocados, bananas, cherries, dates, grapes, nectarines, papaya, peaches, persimmons, pears, and strawberries -These foods turn brown from enzymatic browning which occurs in the presence of three substances phenolic compounds found within the cells; polyphenol oxidase enzymes (also known as phenolase, catecholase, tyrosinase); and oxygen which enters when food is cut or bruised -The polyphenol oxidase enzymes turn the color of the phenolic compounds from clear to brown. -These brown compounds called melani, although they look unappetizing, are safe to consume -can add additives such as sulfites, sorbates, and benzoates to prevent browning

multiple fruits

-Pineapples and figs

fruits in human history

-throughout human history fruits have been prized and their seeds transported wherever humans have settled, resulting in the great variety of fruits available today

Which of the fruits below contain more vitamin C than a medium sized orange

-1 medium papaya -1 medium kiwifruit -1 cup strawberries

aggregate fruits

-Blackberries, raspberries, and strawberries

Composition of fruits

-Cellular structure in the pigments of fruits are similar to those of vegetables. -Flavors of fruits are the result of combinations of sugars, acid, phenolic and a romantic aromatic compounds, and essential oils. -Fruits typically have a pH below 5.0. - pectin plays an important role in fruit ripening and the gelling of fruit spreads -Nutritionally fruits are generally low in calories, fat, and protein. -The few fruits that are high in fat or coconut, avocado, and olives. -Fruits are high and water and carbohydrates, the latter providing the majority of their calories. -Some but not all fruits can be excellent sources of vitamin C, B-carotene, iron, or potassium

preparation of fruits

-Cooking alter the taste, texture, color, and shape of fruit, so fruit is often consumed in its raw state. -Cooking fruit adds variety to meals, makes fruit like rhubarb and green apples palatable, and uses over ripe fruits. -Fruits should be prepared using a minimum of water, time, and heat -Most fruit can be kept beyond the growing season by combining it with sugar in the following forms of fruit spreads. PRESERVES: made from whole fruit, halves, or chunks. JAMS: ground or mashed whole cooked fruit. CONSERVES: made from a mixture of fruits, usually including citrus, to which nuts and raisins, but no sugar, are added JELLIES: made from the juice of cooked fruit, with added sugar and pectin. MARMALADES: juice combined with thin slices of fruit and rind, especially citrus fruits BUTTERS: thick and smooth, made from sieved, long cooked fruit usually less sweet than jams and jellies, and more perishable than other fruit spreads

classification of fruits

-Fruits are classified according to the type of flowers from which they develop. -Simple fruits develop from one flower. -Aggregate fruits develop from several ovaries in one flour. -Multiple fruits developed from a cluster of several flowers

purchasing fruits

-Fruits are selected based on appearance, size, color, shape, uniformity, and freedom from defects. -the FOUR grades for fresh fruits are US fancy US No. 1 US No.2 US No. 3 -Fruit selection is based on grading factors as well as seasonal availability and criteria particular to each individual fruit variety -Fruits are available fresh in summer, but they can be obtained throughout the year in various processed forms: (canned, frozen, dried, and juice.) -Refrigerated transport also makes fruit available your year-round from countries with different growing seasons. -Grades for canned or frozen fruits are : US grade A or Fancy US grade B or Choice US grade C or Standard

Discuss the three groups of peptic substances, how they contribute to the ripening of fruits, and how they are used by the food industry

1. protopectin: immature fruit (no gel) 2. pectin (pectinic acids): ripe fruit (gels) 3. pectic acid: overripe fruit (no gel) collectively known as PECTIN which acts as a cementing surface between cell walls and are somewhat responsible for the plants firmness and structure -as a fruit ripens, enzymes convert protopectin to water-soluble pectin -Ripening mechanisms trigger the pectinase enzymes, which break down the pectic substances as the fruit ripens, -degree of fruit softening is related to how many peptic substances were degraded. -Stage of ripeness affects pectin concentration, and it is the pattern extracted from Riip fruits that is used to jail jams and jellies -As fruit continues to ripen and becomes over ripe, all the pectin gradually turns to pectic acid -used commercially to contribute to the gelling of fruit preserves; they use the pulp (pomace) -used in jams as jellies but also used in other foods as an emulsifier, stabilizer, thickener, and texturizer

Define the three classifications of fruits, how they differ, and provide examples of each

1. simple fruits: develop from one flower -peaches, cherries, apples, pears, oranges, lemons, limes 2. aggregate fruits: develop from several ovaries in one flower -blackberries, raspberries, strawberries 3. multiple fruits: develop from a cluster of several flowers -pineapple, figs

Describe the specific signs of ripeness for the following fruits

AVOCADOS: touch, If the skin gives slightly to gentle pressure the fruit is ready for immediate use, thicker avocados can be tested for ripeness by inserting a toothpick in the stem and end, if it moves in and out easily the avocado is ripe GRAPEFRUIT: It is at its best when the skin is shiny and smooth and both ends are flat, avoid grapefruit with pointy ends, thick skins, or deep pores GUAVAS: Select guavas who skins are yellow rather than green and yield to pressure in the middle of fruity guava aroma. LEMONS: Lemons with thin skins and those that are heavy for their size healed more juice than they're thicker skinned lighter counterparts, storing lemons in water will produce twice the juice when squeezed HONEYDEW: ripe honeydews have a waxy feeling, creamy white rind, and honeydew aroma. For best flavor choose one weighing at least 5 pounds MELON: It's difficult to select because they're hard outer rind and subtle color changes. When ripe the stem and become slightly in dented and yields to pressure, another indication of ripeness is a distinctive melon odor coming from stem end JUICE ORANGES: Orange is that feel firm and heavy for their size are the best choice for juiciness

Most fruits are low in fat, but the exceptions are

Avocados, coconut, and olives

Describe the changes that occur when fruits are heated

COLOR: Heating fruit may change the pH which affects the color of some pigments TEXTURE: He drastically softens fruit sometimes to the point of mushiness due to the conversion of the fruits protopectin to pectin, degradation of cellulose and hemicellulose, denaturation of the cell membrane proteins FLAVOR:The flavor substances and volatile compounds that contribute to aroma can be lost during preparation which is why fruits are either served raw or heated only for minimal amount of time

simple fruits

DRUPES: fruits with seeds encased in a pit -apricots, cherries, peaches, plums POMES: fruits with seeds contained in a central core -apples, pears CITRUS FRUITS: -oranges, grapefruits, lemons, limes, kumquats, mandarins

These fruits commonly have their peel scraped for zest to add flavor

Lemon, orange, lime