General Principles * housewife and food nutrients (retains) Food processorFood processor No sharp distinction between home-prepared and factory-processed foods in their nutritional valuesNo sharp distinction between home-prepared and factory-processed foods in their nutritional values Are all mothers good cooks?Are all mothers good cooks? - destruction of nutrients - destruction of nutrients - texture and flavors - texture and flavors

The term “ processing “ covers an enormous field of widely differing treatments carried out for a diversity of purposes * Kind of losses: 1. Intentional losses: - milled cereals ( bran) - vegetables are trimmed - fish eviscerated - foodstuffs extracted from the raw materials ( starches, sugars, fats, protein isolates) 2. Inevitable losses ( cooking, blanching, canning, drying, sterilization) 3. accidental and / or avoidable losses ( due to inadequate control)

Are such losses a matter for concern? -Cannot be answered as a generalization - no evident malnutrition in the community ( have no significance). -- the earliest stages of malnutrition are extremely difficult to diagnose -- some sections of the community may be affected more

Nutritionist vs food scientist Nutritionist -- look to the diet as a whole ( no significance) The food scientist -- any avoidable loss indicates poor commercial practice

Factory processing vs domestic cooking Direct comparisons are rarely possible FP include partial or even complete cooking so factory losses replace those that take place in the home The situation is very complicated -- different results for each nutrient, food, process and factory …et -- experimental conditions ( contradictory)

Background 1. some losses are inevitable - preservation - improvement of palatability - texture and eating properties - creation of new products - removal of inedible parts - elimination of m/o - destruction of toxins * Many of these processes involve heat and water treatment ( both will result in some losses)

Background 2. nutritional losses in food processing refer generally to all nutrients but --- vitamin c and to a lesser extent B1 are the most sensitive --- the other are much more stable *3. manufacturing and processing losses are often in place rather than in addition to what happen in the home

background 4. the relative importance of the food in question as a source of the particular nutrient must be taken into account ( ignorance of poor source) 5. we should look to sections of the community relying on a small No. of foods as a source of nutrients. 6.we have to be careful when we make comparison between fresh and processed food and even between fresh foods.

background 7.beneficial effects should be considered - increase in nutrient availability - destruction of protease inhibitors - destruction of toxins……et *8. losses must be balanced against advantages - pasteurization of milk ( vit. C, B1,B2) - So 2 as a preservatives ( thiamin) 9. Inadequate methods of assessing nutritive value can lead to false conclusions. 10. Availability of foods around the year so it is a non-valid comparison between fresh and processed foods.