Vegetables, Potatoes, Fruits and Juices

Product Type Size Blanched at 100 °C Freezing temp (°C) T (°C) / h (mbar) RM (%) 

A Color 1 Strawberries a Senga Sengana b Hummi Trisca 

Kapsalis et al. [4.12] showed, that the residual moisture content RM of peas should neither be to small nor too high. During 84 days-storage at +43 °C and RM below 5 %, the thiamine content was barely reduced, but the carotene content fell to approx. 36 %. On the other hand, the thiamine content fell at RM 33 % to 81 %, while 50 % of the carotene content was preserved. These and other reasons not discussed here led Kapsalis to the conclusion, that an optimum RM does generally not exist, but only a desirable RM for one type of product under given storage conditions. 

Lime [4.15] described the freeze drying of avocado salad (88.7 % avocado-meat, 4.6 % lemon juice, 0.7 % onion powder, 1.43 % NaCl, and 5.0 % cracker powder) ending with a 

free fatty acids B, peroxides. Two runs have been carried out, marked as 3 and 4 (Fig. I from [4.15]). 

Medas and Simatose [4.13] and Sauvageot and Simatose [4.14] arrived at similar conclusions for strawberries and orange juice. The freezing rate changed the RM and the rehydration differently for different types. Also, the retention of aroma depends not only on the freezing rate but also on the layer thickness of the juice, the original 

Hammami et al. [4.27] determined 0.5 mbar and rSh = 55 °C as the optimum (for quality and operational data) drying conditions for the freeze-drying of apple slices, loaded with 17 kg/m2 and dried in 48-50 h. The rehydration ratio was -0.55 g/g of water removed and the texture loss of rehydrated apples was estimated to be more than 85%. Sa et al. [4.28] used DSC to measure the Tg of freeze-dried Golden Delicious apples after exposure to aw from 0.12 to 0.93. The sorption isotherms are reported. 

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Sources are citrus fruits and juices, melons, berries, and other fruits, peppers, broccoli, potatoes, and many other fruits and vegetables. 

In addition to HPLC/fluorescence, there are references to the use of both APCI and/or ESI with HPLC/MS for the determination of A/-methyl carbamate insecticides in a variety of matrices." Ongoing studies at the US EPA for the determination of /V-methyl carbamate insecticides in nine fmits and vegetables at the 1.0 ngg level are described below. The fruits and vegetables investigated were cranberries, peaches, blueberries, kiwi, carrots, tomatoes, potatoes, lettuce, and grapefmit juice. The purpose of including an account of this work is to illustrate why HPLC/MS/MS is the method of choice for residue work at the 1.0 ng g level, especially for difficult matrices. 

Caffeic acid is generally the most abundant hydroxycinnamic acid in fruit and vegetables. The richest sources are coffee (drink), lettuce, carrots, blueberries, blackberries, cranberries, sweet potatoes (whole, cooked, and raw) and potatoes (Table 2.2). Prunes, peaches, orange juice, apples, tomatoes, grapes, and grape products (Bet6s-Saura and others 1996) also contain small quantities of caffeic acid. 

Preservatives. Sulfur compounds, such as sulfur dioxide and sodium bisulfite, are used commercially to preserve the color of various food products, such as orange juice, dehydiated fruits and vegetables, such as apricots, carrots, peaches, pears, potatoes, and many odiers. Concentrated sulfur dioxide is used in wine-making to destroy certain bacteria. The color preservation of canned green beans and peas is enhanced by dipping the produce in a sulfite solution prior to canning. In 1986, some of these compounds and uses were put under closer regulation in the United States. 

Uses Demeton-s-methyl is a pale yellow oil that has a sulfur-like odor. It is a systemic and contact insecticide and acaricide. It kills insects that feed on plants by sucking juices. It is used to control aphids, sawflies, and spider mites in fruits, vegetables, potatoes, cereals, ornamentals, and forestry. Demeton-s-methyl replaces methyl demeton, a mixture of demeton-s-methyl and demeton-o-methyl sold as systox meta. Demeton-s-methyl is more toxic to insects than demeton-o-methyl. It is available as an emulsifiable concentrate.28,40... 

Disulfides, applied mainly as food and drink preservatives, are found in numerous products bread additives, tea, sweets, seafood, jams, jellies, dried fruit and vegetables, fruit juices, vegetable preserves, potato powder, frozen potatoes, and soup concentrates may be a direct reason of nonallergenic hypersensitivity (Taylor et al. 

Sources. The best dietary sources of potassium are fresh unprocessed foods, including meats, vegetables (especially potatoes), fruits (especially avocados and bananas), and citrus juices (such as orange juice). Most potassium needs can be met by eating a varied diet with adequate intake of milk, meats, cereals, vegetables, and fruits. 

Freshly cut surfaces of fruits and vegetables discolor when exposed to oxygen in the air. Cut three slices of a fruit or vegetable such as apple, potato, avocado, or banana. Leave one piece on the kitchen counter (uncovered). Wrap one piece in plastic wrap and leave it on the kitchen counter. Dip one piece in lemon juice and leave it uncovered. 

In recent years, the conversion of starch to fructose has become a very important commercial process. High-fructose corn syrup (HFCS) is approximately twice as sweet as sucrose. It is used in soft drinks, canned fruits, lactic acid beverages, juice, bread, ice cream, frozen candies, and so on. HFCS can be obtained from a variety of cereals and vegetables, such as corn, wheat, rice, potatoes, and cassava. Corn is the most important source of HFCS because of low costs and excellent utilities of its by-products, corn meal, oil, gluten, germ, and fiber. 

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