填空题

Malnutrition during weaning age--when breast milk is being replaced by semisolid foods--is highly prevalent in children of poor households in many developing countries. While the etiology (病因学) is complex and multifactorial, the immediate causes are recognized as feeding at less than adequate levels for child growth and development, and recurrent infections, including diarrhea, resulting mainly from ingestion of contaminated foods. As a result, many young children, particularly between six months to two years of age, experience weight loss and impaired growth and development.
Studies by investigators in various countries have concentrated on traditional food preparation methods and have resulted in offering cheap and practical answers to these problems based on familiar, indigenous and culturally acceptable home processing practices.
Two such answers have arisen. Firstly, cereal fermentation is used for reducing the risk of contamination under the existing inappropriate conditions for food preparation and storage in many households. Secondly, a tiny amount of sprouted grains flour is used in preparation of weaning foods as a magic way to lessen the viscosity without decreasing energy density.
A method to eliminate pathogenic (致病的) bacteria and inhibit their growth during storage of weaning preparations can benefit nutrition and health in young children considerably. Use of fermented foods for feeding children of weaning age appears to be an effective solution. Fermented foods have lower levels of diarrhoeal germ contamination, they are suitable for child feeding, and can be safely stored for much longer periods of time than fresh foods. The practice has been a traditional way of food preservation in many parts of the world. The antimicrobial properties of fermented foods and their relative higher safety--documented since the early 1900s--have been indicated in a number of studies.
In Ghana, it is common to ferment maize dough before cooking it as porridge. In Kenya, cerealbased porridge and milk are traditionally fermented. Preserving milk in the form of yogurt has been known to many households living in hot climate.
What are the underlying mechanisms by which fermentation processes help to prevent or reduce contamination A possible answer suggests that during the fermentation process foods become more acid. This explains why diarrheacausing bacteria are not able to grow in fermented foods as rapidly as in unfermented ones. It is also hypothesized that some of the germs present in the foods are killed or inhibited from growing through the action of antimicrobial substances produced during fermentation. The fermented foods can, therefore, be kept for a longer time compared to fresh ones. It has been shown that while contamination levels in cooked unfermented foods increase with storage time, fermented foods remain less contaminated.
Whatever the underlying mechanisms, the fact is that the exercise reduces contamination without adding to the household cost both in terms of time and money. Its preparation is easy. The cereal flour is mixed with water to form a dough which is left to be fermented; addition of yeast (酵母), or mixing with a small portion of previously fermented dough is sometimes needed. The dough can then be cooked into porridge for feeding to the child.
Although beneficial, unfortunately the practice is going out of fashion, partly be-cause of current emphasis on the use of fresh foods, particularly for children. For example, a study on the use of fermented foods for young children in Kenya, demonstrated that while foods are still frequently fermented at home for child feeding, their use is becoming less popular, particularly in urban area where commercial products are more available. Clearly they now need to be promoted.
Directions:
The statements below relate to the passage you have just read. Identify whether they are TRUE or FALSE and mark the corresponding letter (T for True and F for False) on the Answer Sheet with a single line through the center.
The fermentation of foods is investigated because it both inhibits food contamina- tion and enhances storability.

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