Abstract
Minerals are constant constituents of animal tissue. They may be essential components for the maintenance of life processes, or they may perform some nonessential but favorable function. Man is omniverous and can live on a diet of animal, vegetable or mineral origin. The sources of minerals are therefore immaterial for man and the other omnivora; but the presence of all these elements in our food supply is essential. All essential elements are beneficial when present in the body in proper balance. Out of balance or in deficiency they lead to diseases and in excess they may be toxic. Various mineral elements are so interrelated in metabolism that their quantitative requirements are interdependent. A deficiency of a given nutrient may exist with respect to its specific function and also in the balance which should be maintained between it and certain other essentials. Conversely, pathological changes may result from relative as well as from absolute excesses of a given element.
During the last two decades, per capita consumption of fresh fruit has increased markedly. Although many believe that this increase has been caused by a heightened concern in health and diet, economic analyses indicates that changes in retail prices and increasing per capita incomes adequately explain the increased consumption of fresh fruit. Also, with more single households and women entering the labor force, the convenience factor of focal preparation has likely caused an increase in the consumption of fresh fruit. Substantial substitution between fresh fruit products has occurred: grapes and strawberries have increasingly substituted for citrus fruit, particularly grapefruit. These results suggest that relative prices for fresh fruits, increasing disposable income, and the changing demographic composition of households have prompted observed increases in the per capita consumption of fresh fruit.
Abstract
NASA is interested in extraterrestrial crop production because it is expected that some future missions may require life support systems that can regenerate food as well as air and water. Such systems must produce a nearly complete human diet within very stringent limits on size and energy consumption. Although many problems remain to be solved by further research, CELSS based on crop production by higher plants appear to be feasible. The feasibility of this approach will be tested in the next several years by a project to build and operate a preprototype system that can recycle oxygen, carbon, water, and nitrogen. If this project succeeds, it will be followed by Space Station experiments to develop cultural methods for weightless plants and ground-based tests of more sophisticated prototypes with human occupants. Readiness to build operational space systems may be achieved as early as the turn of the century.
Sesquiterpene carboxylic acids (SCA) are synthesized by leaf trichomes of a wild tomato species Lycopersicon hirsutum accession LA 1777 and confer resistance to the tomato pests Helicoverpa zea (Boddie) and Spodoptera exigua (Hubner). Larvae of both species exhibited a reduction in survival and growth rate with altered feeding behavior when exposed to SCA in choice and no-choice insect bioassays. Larvae of both species were reared on artificial insect diets with SCA added at 0, 10 and 60 mg SCA per g of diet. All larvae perished in the 60 mg·g–1 treatment which is comparable to the levels of SCA found on LA 1777. H. zea and S. exigua showed about 35% and 60% reduction in survival to adult and 38% to 22% increase in life cycle duration, respectively, in the 10 mg·g–1 treatment relative to the control. Similar reductions in growth rate and survival were observed when larvae were reared on leaves coated with SCA. Choice bioassays with control (0 mg SCA/g leaf) and 60 mg SCA/g treated leaf tissue demonstrated 2.3-fold increase in larval avoidance and 50% reduction in feeding on treated leaves. Our results suggest that breeding for SCA synthesis in tomato would produce lines with increased resistance to the tomato pests H. zea and S. exigua. Backcross breeding procedures using LA 1777 have initiated the introgression of the SCA genes into cultivated tomato germplasm. Studies of inheritance of genes coding for SCA synthesis are underway to reveal allelic interactions and facilitate there introgression into the cultivated tomato germplasm.
manuscript. The authors thank Mr. Yasuhiro Okuno for kindly providing the experimental materials. This research was supported by Diet and Cancer Prevention: Exploring Research Technology, Miyazaki Prefecture Collaboration of Regional Entities for the
Research Center, for kindly providing `Banpeiyu' pummelo and `Ruby Red' grapefruit. This research was supported by Diet and Cancer Prevention: Exploring Research Technology, Miyazaki Prefecture Collaboration of Regional Entities for the Advancement of
Plants are the foundation for a significant part of human medicine and for many of the most widely used drugs designed to prevent, treat, and cure disease. Folkloric information concerning traditional remedies for disease has had inestimable value in establishing familial and cultural linkages. During the 20th century, modern medical science in the U.S. and other developed countries ushered in a new era focused on synthetic medicines. Even though many of these compounds were based on natural compounds found in plants, the drive towards synthetic pharmaceuticals created a knowledge gap concerning the health functionality of plants, crops, and food. Paralleling this development, biochemists and nutritional scientists pioneered the discovery of vitamins during the early decades of the 20th century. This research paved the way for dietary guidelines based on empirical data collected from animal feeding trials and set the stage for the current emphasis on phytonutrients. Three primary stages characterize the use of fruits and vegetable in human health. The first stage concerns the observation that many fruit and vegetable crops were originally domesticated for their medicinal properties. Making their way into the diet for this purpose, fruit and vegetable crops remained on the fringe from a culinary point of view. The second stage began when the role of vitamins became more widely understood, and fruit and vegetable plants were quickly recognized as a rich source of certain vitamins, minerals, and fiber. At this point, they became more than just an afterthought in the diet of most U.S. citizens. Cartoon icons such as Popeye made the case for the health functionality of leafy greens, while parents schooled their children on the virtues of carrots (Daucus carota), broccoli (Brassica oleracea), and green beans (Phaseolus vulgaris). This renaissance resulted in large increases in fresh fruit and vegetable consumption across the country, a trend that continues to this day. The third phase can be characterized by the recognition that fruit and vegetable crops contain compounds that have the potential to influence health beyond nutritional value. These so-called functional foods figure prominently in the dietary recommendations developed during the last decades of the 20th century. In recent years, surveys suggest nearly two-thirds of grocery shoppers purchase food specifically to reduce the risk of, or manage a specific health condition. Evidence abounds that consumers, including Baby Boomers, choose foods for specific health benefits, such as the antioxidant potential of vegetables, suggesting high levels of nutritional literacy. Clinical and in vitro data have, to some degree, supported the claims that certain foods have the potential to deter disease, however much research remains to be conducted in order to definitively answer specific dietary-based questions about food and health.
Abstract
Starch granules were extracted from maize (Zea mays L.) endosperm of mature F2 kernels of IA5125 × IA453 normal, amylose-extender (ae), dull (du) waxy (wx), and ae du wx and from ae du wx F2 kernels harvested at the fresh market stage of development. Samples were digested for 1.5 hours with hog pancreatic α- amylase and Rhizopus II amyloglucosidase. The mature and immature ae du wx samples were usually digested significantly more than the other 4 genotypes, while ae was digested significantly less than the others. Digestion of starch granules from mature and immature ae du wx kernels did not differ. The sweet corn background used had little effect, since our observations of the single mutant genotypes were similar to those in a dent background. Clearly, ae du wx starch granules do not reflect the reduced digestibility associated with ae, and thus cultivars homozygous for ae du wx are not inferior with respect to their ability to supply carbohydrates to the diet.
The importance of folic acid in the human diet has been recognized in recent years by major increases in government recommended allowances. Red beet (Beta vulgaris L.) is an important vegetable source of folic acid, however little is known about the extent of variation for native folic acid content in red beet germplasm. A total of 18 red beet entries, including 11 hybrids (F1) and seven open-pollinated cultivars (OP), were evaluated for free folic acid content (FFAC) in replicated field experiments during 1993 and 1994. Significant differences among entries were detected in all studies. FFAC ranged from 3.3 to 15.2 μg·g-1 on a dry mass basis. A significant entry × year interaction was detected. Changes in rank of entries between years were minimal among F1 hybrids, while the changes in rank among OP cultivars were large. These data demonstrate significant variability among cultivated red beet germplasm sources for FFAC. Entries with high FFAC may be useful for increasing levels of this vitamin in red beet.
Anthocyanins are protective pigments that accumulate in plant organs such as fruits and leaves, and are nutritionally valuable components of the human diet. The MYB10 transcription factor (TF) plays an important role in regulating anthocyanin biosynthesis in Malus crabapple leaves. However, little is known about how the promoter regulates McMYB10 expression and influences the substantial variation in leaf anthocyanin accumulation and coloration that is observed in different crabapple cultivars. In this study, we analyzed leaf coloration, anthocyanin levels, and the expression levels of McMYB10 in the leaves of 15 crabapple cultivars with three leaf colors at various development stages, and showed that the expression of McMYB10 correlates positively with anthocyanin accumulation. We also examined the relationship between the number of R6 and R1 elements in the McMYB10 promoters of the different cultivars and the pigmentation of the new buds of spring-red cultivars, as well as the methylation level of the McMYB10 promoters at different development stages in three representative crabapple cultivars. The ratio of R6/R1 minisatellites in the promoters correlated with the color and anthocyanin accumulation in new crabapple buds, and we concluded that the differences in promoter structure and methylation level of the McMYB10 promoters coordinately affect the leaf color of crabapple cultivars.