Vitamin food processing

Food process optimi2ation measurements may link a single chemical such as a vitamin, or a physical change such as viscosity, to process conditions and to consumer acceptance. Retention levels of ascorbic acid [50-81-7] C HgO, or thiamine can often be used as an indicator of process conditions (see... 

Rich sources of vitamin A include dairy products such as milk cheese, butter, and ice cream. Eggs as well as internal organs such as the Hver, kidney, and heart also represent good sources. In addition, fish such as herring, sardines, and tuna, and in particular the Hver oil from certain marine organisms, are excellent sources. Because the vitamin A in these food products is derived from dietary carotenoids, vitamin A content can vary considerably. Variation of vitamin A content in food can also result from food processing and in particular, oxidation processes (8). 

Bioavailability can be influenced directly or indirectly by many physiological, pathological, chemical, nutritional, and processing conditions. Discussion in this chapter will be limited to unit food processing effects upon the bioavailability of nutrients from plant protein foods. The bioavailability of amino acids, carbohydrates, lipids, vitamins and minerals from processed foods will be selectively reviewed. Amino Acids... 

Niacin is relatively stable to most food-processing operations. It is stable to exposure to air and resistant to autoclaving (and is therefore stable to pasteurization and UHT treatments). The amide linkage of nicotinamide can be hydrolysed to the free carboxylic acid (nicotinic acid) by treament with acid but the vitamin activity is unaffected. Like other water-soluble vitamins, niacin can be lost by leaching. 

The six principal B6 vitamers are widely distributed in foods (102,103). They include pyridoxine (PN), pyridoxal (PL), pyridoxamine (PM), and their 5 -phosphate esters, pyridoxine phosphate (PNP), pyridoxal phosphate (PLP), and pyridoxamine phosphate (PMP) (Fig. 5). The predominate B6 vitamer in animal-based foods is PLP, whereas plant products generally contain PN and PM or their phosphorylated forms. Conjugated vitamers in the form of PN-glycosides have also been isolated from plant-based foods. Pyridoxal is readily converted to PM during cooking and food processing. Total vitamin B6 is the sum of the six principal vitamers inclusion of the conjugated forms depends on the extraction procedure. 

The conjugated forms of vitamin B6 appear to be less available than the six principal vitamers (102,104-106) a relative value of 58% has recently been suggested for PN-glycoside in humans (107). In addition, food processing and storage can induce changes that reduce the bioavailability of vitamin B6 (102). Thermal processing and low moisture conditions can induce reductive... 

Source From E. deRitter, Stability Characteristics of Vitamins in Processed Foods, Food Technol., Vol. 30, pp. 48-51,54, 1976. 

Thiamin is one of the more unstable vitamins. Various food processing operations may considerably reduce thiamin levels. Heat, oxygen, sulfur dioxide, leaching, and neutral or alkaline pH may all result in destmction of thiamin. Light has no effect. The enzyme is stable under acid conditions ... 

Bender, A.E. 1971. The fate of vitamins in food processing operations. In Vitamins, ed. M. Stein. London Churchill Livingstone. 

L-Ascorbic acid (vitamin C, ASA) is produced on a scale of 80 kt a-1 worldwide it is used in food supplements, pharmaceutical preparations, cosmetics, as an antioxidant in food processing and a farm animals feed supplement [145]. It is synthesized in vivo by plants and many animals, but not by primates, including Man, or microbes. 

Ascorbic acid 2-phosphate and triphosphate are more stable to atmospheric oxidation than ascorbate and are used in food processing. They have the same biological activity as ascorbic acid on a molar basis, because they are substrates for intestinal phosphatases. Ascorbic acid 2-sutfate is a metabolite of the vitamin in some species and has litde or no biological activity. 

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