Intro to Foods chapter 14 Fruits

What part of the plant are fruits?

Fruit is a distinctive organ that develops from the flower's female tissue, the ovary, and encloses the maturing seeds. Most fruits are simply the thickened ovary wall or incorporate nearby tissues as well.

Fruits

Nature's desserts Available in most every shape & color Fruits & seeds from all over the world Fruits and Veggies - More Matters campaign Minimum of at least 5 servings of vegetables & fruits 3 vegetables & 2 fruits

acidity of fruits

*Acidity of Fruits -Acids cause most fruits to have a pH value below 5.0 -Tartness related to acidic content - Lemons, limes, cranberries Have lowest pH (2.0) -Least acidic fruits More bland & sweet -Those with pH above 4.5 Most often serve as vegetables

Fruits preparation

*Enzymatic Browning -Cold temperatures --Slows enzyme activity, but not complete enzyme inhibition -Coating with sugar or water ---Prevents exposure to oxygen -Antioxidant --Ascorbic acid (vitamin C) & sulfur compounds use up oxygen

phenolic compounds

*Responsible for browning & bruising *Tannins -Found mostly in unripe fruits, giving them a bitter taste and leaving astringent in mouth *Some fruits that contain phenolic compounds... -Apples, apricots, avocados, bananas, cherries, dates, grapes, nectarines, papayas, peaches, persimmons, pears, strawberries

cooking medium

*The balance or imbalance between the sugar concentration in the cooking liquid and the fruit influences the outcome. *To retain shape -Cook in sugar syrup -Sugar syrup to retain structure -Semi-permeable cell walls become permeable to larger molecules with heat - sugar diffuses in *To prepare sauce -Cook in water -Water to break down structure -Water in, sugar out

Classification of fruits

*classified according to # of ovaries Classification Exceptions -Is a tomato a fruit or a vegetable? --Botanically it is fruit Nuts are fruits -Nuts are seeds instead of fleshy fruit -Grouped separately Rhubarb -is a vegetable, but treated as a fruit

Fruits as Functional Foods

*fruits important in growth of functional foods *Some, but not all, are rich in... -Vitamins and minerals, and... -Antioxidants - E.g., lycopene (linked to reducing cancer risk) -- anthocyanins in berries - Vit A, C, E -Polyphenols - Linked to decreased risk of high blood pressure, heart disease, stroke -Fiber - Linked to decreased risk of colon cancer & high blood pressure

Food Additives in Fruits

-Additives added dried fruits to prevent browning -Sulfites, sorbates, benzoates -Some are sensitive to sulfites, so vitamin C can be used instead

Selecting Fresh Fruits

-Most frequently consumed (descending order)... Bananas, apples, watermelons, oranges, cantaloupe, grapes -Look at grade -Buy during peak season

pectic substances and juice cloudiness

-Pectin substances can cause cloudiness -Unappealing in certain juices - e.g., apple juice -Clarification process involves adding enzymes, such as pectinases, to break down pectin compounds

albedo

-White, inner rind of citrus fruits -Rich in pectin & aromatic oils -think of oranges

Pectin

Cell cement;partially responsible for firmness and structure. Produced at height of ripeness; extracted to make jams & jellies

Fruits composition

Cellular Structure & Pigments -Similar to vegetables -Organic acids --Volatile & nonvolatile Pectic substances -Three types: Protopectin, pectin, pectic acid Phenolic compounds -Also known as tannins

ripening

H2C=CH2 *respiration during metabolic processes *Ethylene gas - Produced naturally by fruits and vegetables - Speeds ripening process - Production increased when fruit is peeled or sliced - May be used commercially (bananas) *Color - Synthesis of new pigments - Breakdown of chlorophyll ripening of green tomato in Rm Temp.???

Protopectin

Large, insoluble molecule in young fruit; enzymes transform into pectin as fruit ripens; doesn't contribute to gelling

organic acids

Organic Acids -Volatile - Vaporize during heating -Nonvolatile - Do not vaporize; leach out when cooked in water -Common acids... --Citric - In citrus fruits & tomatoes --Malic - In apples, apricots, cherries, peaches, pears, strawberries --Tartaric - In grapes --Oxalic - Rhubarb --Benzoic - In cranberries

pectic acid

Produced when fruit is overripe; doesn't contribute to gelling

Cellular Structure & Pigments

Similar To Vegetables CHO - sugar and starch Low protein and Little fat [Coconut (35%), avocado (17%)] Water ~ 85% High vitamins, especially rich in vit C and precursors of vit A, usually low in Bs (Oranges for Folate) Variation: maturity, ripeness, variety, climate, processing, storage... Usually low in minerals except: Ca, Fe and Phosphorus Phytochemicals Kcals, higher than vegetables (Fructose) Fiber (whole better than processed) 17

Fruits: type of flower

Type of Flower Simple -Drupes: Fruit w/ Seeds Encased In A Pit (Apricots Cherries Peaches Plums) -Pomes: Fruit w/ Seeds In A Central Core (Apples Pears) Aggregate: Several Ovaries in One Flower (Blackberries Raspberries Strawberries) Multiple: Cluster of Several Flowers (Pineapples Figs)

ripening process

protopectin (immature fruit, no gel) ---> pectin (ripe fruit, gels) ---> pectic acid (overripe fruit, no gel) -Fruit ripens, then becomes overripe -Pectin becomes pectic acid