196 The nutrition handbook for food processors 8.2 The nutritional importance of plants Plants are the staple food for the vast majority of the worlds population. It is known that many staple plant foods are deficient in essential nutrients and, con- sequently, malnutrition is widespread. It has been estimated that over 100 million children worldwide are vitamin a deficient and improving the vitamin A content of their food could prevent as many as two million deaths annually in young chil- dren. This is apart from the deficiencies in iodine intake, resulting in goitre, and in iron-deficient anaemia which are estimated to affect millions in the develop- ing world. There is also an important need to improve the amino acid content of legume proteins that are deficient in essential sulphur amino acids. Nutritional deficiencies can lead to a reduction in immune responsiveness, rather than a spe cific attributable disorder, making it difficult to establish clearly how many people are suffering from malnutrition In the developed world all public health authorities are urging consumers to onsume more plant-based foods as part of a healthy diet. There is a significant body of evidence to suggest that the traditional Mediterranean diet, rich in plant foods, reduces the risk of many age-related diseases. Epidemiological studies show a strong and consistent inverse relationship between fruit and vegetable intake and the risk of cardiovascular diseases and some cancers. An explosion of interest in trying to define what are the factors in fruit and vegetables which might be responsible for these observations has not yet led to a clear set of expla nations although many theories abound. Plants contain 17 mineral nutrients, 13 vitamins and numerous phytochem cals that have been shown to have potentially beneficial effects on health espe cially against the initiation or progression of degenerative diseases. Almost all human nutrients can be obtained from plant foods, the exceptions are vitamins B12 and D. However, the adequacy of a plant diet in delivering a health benefit from a specific component will depend on the amount ingested and its bioavail- ability. Many beneficial plant compounds that are associated with the plant cell wall are not easily bioavailable. Any way in which overall levels can be increased will help overcome this difficulty. 8.3 Strategies for nutritional enhancement There is no single approach to the improvement of the nutritional quality of plant foods since this is affected by a wide variety of factors. Amongst these are The application of traditional breeding methods to select for varieties with an ncreased level of the bioactive compound a reduction in the content of antinutritional factors The use of genetic manipulation to introduce new traits in plants Improvements in handling, storage and food processing technologies Each of these approaches has a role to play but genetic manipulation prov mechanism for the improvement of nutritional quality that overcomes the pro- blem of the aDsence of a specific biochemical pathway in a staple crop8.2 The nutritional importance of plants Plants are the staple food for the vast majority of the world’s population. It is known that many staple plant foods are deficient in essential nutrients and, con￾sequently, malnutrition is widespread. It has been estimated that over 100 million children worldwide are vitamin A deficient and improving the vitamin A content of their food could prevent as many as two million deaths annually in young chil￾dren.4 This is apart from the deficiencies in iodine intake, resulting in goitre, and in iron-deficient anaemia which are estimated to affect millions in the develop￾ing world. There is also an important need to improve the amino acid content of legume proteins that are deficient in essential sulphur amino acids. Nutritional deficiencies can lead to a reduction in immune responsiveness, rather than a spe￾cific attributable disorder, making it difficult to establish clearly how many people are suffering from malnutrition.5 In the developed world all public health authorities are urging consumers to consume more plant-based foods as part of a healthy diet. There is a significant body of evidence to suggest that the traditional Mediterranean diet, rich in plant foods, reduces the risk of many age-related diseases. Epidemiological studies show a strong and consistent inverse relationship between fruit and vegetable intake and the risk of cardiovascular diseases and some cancers. 2 An explosion of interest in trying to define what are the factors in fruit and vegetables which might be responsible for these observations has not yet led to a clear set of expla￾nations although many theories abound. Plants contain 17 mineral nutrients, 13 vitamins and numerous phytochemi￾cals that have been shown to have potentially beneficial effects on health espe￾cially against the initiation or progression of degenerative diseases. Almost all human nutrients can be obtained from plant foods, the exceptions are vitamins B12 and D. However, the adequacy of a plant diet in delivering a health benefit from a specific component will depend on the amount ingested and its bioavail￾ability. Many beneficial plant compounds that are associated with the plant cell wall are not easily bioavailable. Any way in which overall levels can be increased will help overcome this difficulty. 8.3 Strategies for nutritional enhancement There is no single approach to the improvement of the nutritional quality of plant foods since this is affected by a wide variety of factors. Amongst these are: • The application of traditional breeding methods to select for varieties with an increased level of the bioactive compound. • A reduction in the content of antinutritional factors. • The use of genetic manipulation to introduce new traits in plants. • Improvements in handling, storage and food processing technologies. Each of these approaches has a role to play but genetic manipulation provides a mechanism for the improvement of nutritional quality that overcomes the pro￾blem of the absence of a specific biochemical pathway in a staple crop. 196 The nutrition handbook for food processors