AN OVERVIEW OF IMPORTANCE OF ENRICHMENT IN FOOD PROCESSING – FOOD SCIENCE AND TECHNOLOGY PROJECT TOPICS AND MATERIALS
This seminar looked at the benefits of food enrichment in food processing. Various enrichment items like vitamin A, Iron and Iodine were discussed. These will help add to the nutrients, which were absent or removed during food processing. This work also looked at the fortifying agents in salt (iodine and iron) milk and margarine (vitamin A and D), diet beverages (vitamins and minerals) among others. Food enrichment helps to treat or help prevent nutritional deficiencies and hence promote the general well being of the generality of the population.
The nutritional status of the population is one of the important factors in determining the quality and productivity by a population, which in turn will affect, national productivity. In the long run, good nutritional status contributes to the social and economic development of a nation. However, many nutritional studies, particularly in developing countries, have indicated that certain segments of the population suffer from one or more nutrient deficiencies, which can have serious effects on their health and productivity. (Tannen baum and Young, 1979).
As in many other developing countries, three major nutritional (especially micronutrient) deficiencies are regarded as public health problems in Indonesia, iodine deficiency disorders, vitamins A deficiency and iron deficiency anaemia. The government of Indonesia has instituted programmes to cope with these three deficiencies of which is a food fortification programme.
Nutrient supplementation of foods was mentioned for the first time in the year 400BC by the Persian physician Melanpus, was suggested adding iron filing to wine to increase soldiers “potency”. In 1831 the French physician Boussingault urged adding iodine to salt to prevent goitre. However, it was between the first and second world wars (1924-1944) that supplementation was established a measure either to correction or prevent nutritional deficiencies in populations or to restore nutrients lost during food processing. Thus, during this period, the adding of iodine to salts, vitamins A and S to margarine, vitamin D to milk and vitamins B1, B2, niacin, and iron to flours and bread was established. (Murphy, 1996).
Currently, food fortification encompasses a broader concept and might be done for several reasons. The first is to restore nutrients lost during food processing, a process known as enrichment. In this case, the amount of nutrients added is approximately equal to the natural content in the food before processing. A second reason is to add nutrients that may not be present naturally in food, a process known as fortification. In this case, the amount of nutrient added may be high than that presence before processing.
Fortification also standardizes the contents of nutrients that show variable concentrations. A typical example is the addition of vitamin C to orange juice to standardize vitamin C concentration and compensate for changes due to seasonal and processing variations. Finally, for technological purposes, a preservative or colouring agents are added to processed foods.
Therefore, depending on the reasons for adding nutrients, objectives may be to maintain the nutritional quality of foods, keeping nutrients levels adequate to correct or prevent specific nutritional deficiencies in the population at large or in groups at risk of certain deficiencies (i.e., the elderly, vegetarians, pregnant women etc) to increase the added nutritional value of a product (commercial view), and to provide certain technologist functions in food processing (Borenstain, 1979).
According to these principles, currently in several countries nutrients are added to a wide variety of food carries, such as cereals, flours, bread, milk, margarine, infant formulas, soymilk, orange juice, salt, sugar, monosodium glutamate, tea, dietetic beverages and even parenteral and enteral solutions, most fortifying agents are vitamins and minerals and in some cases essential amino acids and proteins. These additions have helped to solve public health problems, such as salt iodization to prevent goitre (Tannenbaum and Marcel, 1979).
Several terms besides fortification are used for the addition of nutrients to foods: restoration, enrichment, standardization and supplementation (Tannenbaum 1979, Richardson, 1993).
Restoration is the addition of a nutrient to a food in order to restore the original nutrient content. Enrichments the addition of nutrients to foods in accordance with a standard quality as defined by food regulations. Both restoration and enrichment programmes usually involve the addition of nutrients that are naturally available or present in the food product.
Standardization is the addition of nutrients to foods compensate for natural variation, so that a standard level is achieved. Standardization is an important step to ensure a consistent standardized quality of the final product.
Supplementation is the additions of nutrients that are not normally present pr are present in only minute quantities in the food. More than one nutrient may be added, and they may be added in high quantities. As compared with restoration and standardization, fortification has a special meaning: The nutrient added and the food chosen as a carrier have met certain criteria, so that the fortified product will become a good source of the nutrients for a targeted population. Nutrients added for food fortification may or may not have been present in the food a carrier originally.
OBJECTIVE OF THE STUDY
This seminar investigated the importance of food enrichment in food processing.
Effectiveness of Food Fortifications Programmes
Food fortification differs from other programmes that involve the addition of nutrients to foods. Fortification is a nutritional intervention programme with a specifically defined target, and fortified products are expected to become a main source of the specific added nutrient.
Consequently, food fortification is expected to help prevent nutritional inadequacy in targeted populations in which a risk of nutrients deficiency has been identified. The criterion of the effectiveness of a food fortification programme is whether the nutritional and health status of a targeted population has been improved.
The effectiveness of a food fortification programme depends on whether or not the fortified food is accepted, purchased and consumed by the targeted population. Factors such as the quality, taste and price of the fortified products will play important poles in determining the effectiveness of the fortification programmes. Several other important factors that should be considered carefully in designing food-fortification programmes are the followings.
- The food chosen as the carrier should be consumed in sufficient quantities to make a significant contribution to the diet of the targeted population. Salt, sugar, flour, monosodium glutamate (MSG), and cooking oil have been used. Other foods should be explored, especially with reference to the specific food habits and preferences of targeted populations.
- The addition of nutrients should not create an imbalance of essential nutrients. This is especially important for doubly stripy or multiply fortified foods. In which interaction among the added nutrients that are naturally present in the food carrier is likely to occur.
- The added nutrient should be stable under normal conditions of storage and use. Data on the stability of the added nutrient are also important for labeling purposes. The price of the fortified food should be affordable for the targeted population.
- Programmes of quality assurance and control of fortified food can be more easily implemented if the fortification programme is centralized and involves mass production.
- The food should be distributed to as much of the targeted population as possible.
Nutrient stability under normal conditions of storage and use is one of the important factors determining the effectiveness of a food – fortification programme. From a technical stand point, nutritional stability during formulation, preparation and processing is very crucial in determining the effective production of fortified foods. The following factors relating to nutrient stability are important for the manufacturers of fortified foods (Richardson, 1993).
- The technologist needs to know the extent to which food processes and distribution systems could affect nutrient retention, at the same time, the technologist needs appropriate data to develop strategies for minimizing the losses caused by nutrient instability.
- The quality, legislative and marketing specialists need adequate information on nutrient stability, especially to enable them to make statements or claims on labels and advertising.
- The accountants needs to be aware of the stability data to establish and justify expenditures on potential modifications of processing techniques, the cost of nutrient premises e.t.c.
- The nutritionist needs to be aware of the stability data to assess the choices and ultimately, the supply of nutrient(s) for consumers. Nutrient stability is affected by physical and chemical factors. Although many factors may cause serious nutrient degradation, measures can be developed to minimize losses by applying proper technology which includes application of a protective coating for an individual nutrient, addition of antioxidants, control of temperature, moisture and pH and protection from air, light and incompatible metals during processing and storage.
In this paper, several means to reduce the magnitude of degradation will be discussed, especially with regard to vitamin A, iodine, and iron.
Vitamin A is a critical micronutrient, essential for night visions and for the maintenance of skin and mucosal integrity. An early sign of vitamin A deficiency is night-blindness – severe vitamin A deficiency may result in permanent blindness. Vitamin A is still a major nutritional problem in Indonesia as well as in many other parts of the world. The main intervention programmes against Vitamin A deficiency administered by the Indonesia government are nutrition education, distribution of vitamin A capsules and fortification of selected widely consumed foods.
Fortification of foods with vitamin A has been shown to be a very promising strategy. A pilot project on vitamin A fortification of monosodium glutamate (MSG) in three provinces has resulted in reduction of the prevalence of vitamin A deficiency. Further developments are dependent on overcoming the odour changes caused by fortification of MSG with vitamin A. other foods, such as palm oil and noodles, have also been considered as carriers for vitamin A.
Vitamin A occurs in many forms, such as retinol (alcohol), retinal (aldehyde), retinyl acetate or retinyl palmitake (esters) and provitamin A carotenoids (b-carotene, a-carotene, etc). Vitamin A is relatively unstable under normal storage conditions, particularly in harsh environments. The instability is mostly due to its chemical structure, which contains many double bonds susceptible to degradation.
To minimize the degradation of vitamin A, several approaches have been introduced. Since vitamin A is sensitive to atmospheric oxygen (the alcohol form of vitamin A is less stable than the esters), it is normally available commercially as preparation protected by a coating that includes antioxidant(s) (Murphy, 1996), there has been only one major supplier of vitamin A (as retinyl palmitate or acetate) for food fortification, Hoffman – La Roche of Switzerland.
Antioxidants that may be added to vitamin A premixes are butyrate hydroyanisole (BHA), buty lated hydroxytoluene (BHT) and a – tocopherols (vitamin E). The use of vitamin E as an antioxidant is gaining popularity. Trace metals (especially iron and copper) and ultraviolet light accelerate the degradation of vitamin A. The stability of vitamin A is also affected by acidity. Below a pH of 5.0, vitamin A is very unstable.
Iron and Iodine:
Iron deficiency is the most widespread nutritional problem in the world. In Indonesia the prevalence of anaemia among pregnant women, children under five years of age and women workers is 64%, 55% and 30%, respectively. Iron deficiency has adverse effects on resistance to infection, morbidity and mortality from infections disease learning processes, behavior, physical condition and productivity.
One important factor that should be carefully assessed in the preparation of mineral premixes (as ingredients for food fortification) is the type of salt to be fortified. Iron is usually supplied in the form of ferric phosphate, ferric pyrophosphate, ferric sodium pyrophosphate, ferrous gluconate, ferrous lactate, ferrous sulphate or reduced iron, where as iodine is normally supplied in the form of potassium iodine or iodate.
Factors to be considered thoroughly in the formulation for food fortification especially for iron:
- Solubility: Ferrous salts are more soluble than ferric salts.
- Oxidative State: Ferrous salts can be utilized more efficiently than ferric salts, however, ferrous salts are also more reactive in food systems.
- Ability to form Complexes: Ferric iron generally has a greater tendency to form complexes than ferrous iron; the formation of complexes will greatly reduce iron bioavailability.
In the preparation of iron as an ingredient for food fortification, the possibility that the iron will react or associate with other nutrients need to be explored. The present of metal ions (such as iron) may have a detrimental effect on quality of measures are not properly taken. Iron has been shown to speed up vitamin degradation (especially vitamins A and C and thiamine), catalyze the oxidative rancidity of oils and fats, and produce undesirable changes (colour, off flavour etc).
EFFECTS OF PROCESSING ON THE STABILITY OF ADDED NUTRIENTS
The stability of nutrients is affected by many chemical and physical factors. Consequent, processing parameters must be selected and controlled during the processing of fortified food to minimize nutrient losses.
Compared with vitamins, minerals (iodine and iron) are very stable under extreme processing conditions. The primary mechanism of loss of minerals is through of water-soluble materials (Tannenbaum 1979). Vitamin A, on the hand, is very labile in the processing environment. In the form of retinol, vitamin A is more labile than its ester form, for this reason, vitamin A esters are usually used for food fortification.
Effects of High Temperature Treatment on Nutrient (Vitamin) Stability
Because high temperatures may be used in the manufacture of fortified foods, measures must be taken to minimize losses from thermal degradation. Drying is a processing method that uses high temperatures, and it has many applications in the manufacturing of fortified food. Drying is usually performed using several combinations of time and temperature, such as 9 to 12 hours at 50ºc, 2 to 3 hours at 95ºc, or 2 to 5 seconds at 140ºc. To minimize nutrient losses, the use of lower combinations of time and temperature is desirable, which can be achieved by either increasing the surface area or reducing the pressure during the drying process.
Oven drying is the most common method. Pasta products, for example may be dried in an oven for 9 to 12 hours at 50ºc or for 2 to 3 hours at 95ºc. O’Brien A. and Roberton (1993) reported that b-carotene was more stable than the ester form of vitamin A during oven drying. During processing of macaroni, oven drying for 9 to 12 hours at 50ºc resulted in a 14% loss of vitamin A. However, the same treatment caused the loss of only approximately 5% of b-carotene. Furthermore, drying for 3 to 5 hours at 95ºc caused the destruction of 23% of vitamin A but only 8% of b-carotene.
Drum drying is often used for manufacturing fortified food in powdered form. The advantage of drum drying over conventional oven drying is that higher temperatures can be used with a processing time of only 2 to 30 seconds. The combination of high temperature and short time (HTST) maximizes nutrient retention. Furthermore, the drum dryer is usually used for liquid food slurries. Hence, the material may reach a very high temperature as it forms a film over the drum surface. The formation of this film during drying may offer some protection to the nutrients from oxidative damage, especially in comparison with similar HTST processes, such as the extrusion process.
Spray drying is another technique that can be used for manufacturing fortified food. Besides time-temperature combinations, other measures to prevent or minimize the contact of sprayed food products with oxygen need to be applied. During spray drying, a fine spray of food is introduced into the drying chamber where it encounters a stream of hot air, which produces rapid drying. The spraying process greatly increases the contact of the food with oxygen, thus accelerating oxidative damage.
Several ways to minimize oxidative damage have been introduced, including the addition of antioxidants and the application of coating materials and capsulation. Coating material can be applied by using sucrose in a raw material formation (Johnson et al, 1988) showed that a coating containing at least 10% sucrose was needed to offer good protection from oxidative attack during spray drying. They also noted that, if possible, addition of 15% to 20% of sucrose to the raw material formation is desirable, since it offers greater protection from oxidation.
Another food processing operation that uses high temperatures is the extrusion process. Extrusion is very popular for manufacturing snack foods and ready-to-eat breakfast cereals. Extrusion has several advantages over other methods, since it is a very versatile process that includes several operations at once: mixing, cooking and forming. Several parameters are important in determining the quality of the final product including temperatures (100º to 140ºc or higher), moisture content, coating system and oxygen as well as other parameters characteristics of the extrusion process, such as pressure, through put rate.
Food Products Fortifying Agent
Salt Iodine, iron, flour
Milk and margarine Vitamins A and D
Diet beverages Vitamins, minerals
Soymilk, orange juice Calcium
Ready to eat cereals Vitamins, minerals
Infant formulas, cookies Iron
CONCLUSION AND RECOMMENDATIONS
Food fortification will continue to be an important tool, not only to treat or prevent specific nutritional deficiencies, but also to promote a general state of well-being in different populations and possibly to prevent certain chronic diseases. The identification and development of fortifying agents that will guarantee product quality and high bioavailability are technological and scientific challenges.
Some options for the future are the microencapsulation of nutrients, the use of nutrient bioavailability stimulants (addition of ascorbic or other organic acids to promote iron absorption), and the elimination of inhibitors of mineral absorption in the intestine (e.g. phytates).
It is recommended to fortify food in order to increase the content of essential micronutrients in a food, irrespective of whether the nutrients were originally in the food before processing or not. Iodine should be added to salt to prevent goitre. Vitamin C should be added to orange juice to standardize vitamin C concentration and compensate for changes during due to seasonal and processing variations. Whereas, food fortification should be done to reduce the risk of diet – related chronic diseases. These additions will help to solve public health problems.
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