Current Nutrition & Food Science - Volume 7, Issue 1, 2011

Amaranth is a highly nutritious and non-allergenic crop with remarkable nutraceutical properties. Seed protein extracts following enzymatic digestion have been shown to inhibit Angiotensin Converting Enzyme (ACE). A possible mechanism of action of ACE inhibitor (ACEi) peptides involving the induction of Nitric Oxide (NO) production through endogenous Nitric Oxide Synthase (eNOS) activation has been proposed. The presence of lunasin, a peptide with proven antitumoral properties, has been confirmed in amaranth seeds and the gene encoding the amaranth lunasin peptide appears homologous to the bifunctional inhibitor/lipid transfer protein/seed storage 2S of the albumin family. Amaranth consumption has been shown to improve the plasma lipid profiles in animals. Methanolic extracts of amaranth have demonstrated anti-hyperlipidemic, anti-diabetic and anti-helmintic properties, while aqueous extracts have demonstrated anti-diarrheic, anti-fungal and anti-malarial properties. Specific polyphenols such as rutin, isoquercetin and nicotiflorin and some phenolic acids and amides with antioxidant effects have also been found in amaranth seeds. The aim of this mini-review is to provide an overview of the nutraceutical properties of amaranth.

For the last couple of decades, there has been a surge of global interest pertaining to the beneficial nutritive effects of bioactive phytochemicals like γ- oryzanol (γ-OZ), obtained from crude rice bran oil (RBO), which is manufactured from rice bran, a by-product of rice processing. Oryzanol, although presumed to be a single component initially, was shown to be a mixture of ferulic acid esters of triterpene alcohols and plant sterols. The γ-OZ component can be simultaneously separated and quantified by high performance liquid chromatography, once the RBO has been extracted from rice bran by solvent extraction using food grade n-hexane or by supercritical fluid extraction technology. A number of potentially therapeutically useful biological activities have been reported for γ-OZ, in terms of improvement of the plasma lipid pattern of rodents, rabbits, non-human primates and humans, reducing total plasma cholesterol and triglyceride concentration and cholesterol absorption from cholesterol-enriched diets and aortic fatty streaks and simultaneously increasing the high density lipoprotein cholesterol level. Other potential properties of γ- OZ, that have been studied both in vitro as well as in vivo are the modulation of the pituitary secretion, inhibition of the gastric acid secretion, antioxidant action and inhibition of the platelet aggregation. However, these studies were unable to produce unequivocal conclusions and had been conducted on animal species very different from each other, and using diverse experimental methodologies and targets. The current contribution provides a comprehensive review of the chemical constituents, pharmacological profile and the healthcare properties of γ-OZ as a nutraceutical.

Protein synthesis is considered the major pathway for the final utilization of amino acids, however amino acids also enter as key precursors in many other metabolic processes. For instance, the aromatic amino acids (AAA) tryptophan and tyrosine (or phenylalanine) are precursors of serotonin and catecholamines, respectively. By using AAA-enriched or AAA-deprived diets, the key role of serotonin and catecholamines in modulating some aspects of mood, cognition, social interactions and perhaps eating behaviour was demonstrated.

Food allergies are more prevalent during childhood. Relativity few foods are responsible for the vast majority of significant food-induced allergic reactions: milk, egg, peanuts, tree nuts, fish and selfish. The prognosis of these food allergies is not always toward spontaneous tolerance. Predictive factors of not developing spontaneous tolerance were: high levels of specific IgE to food proteins, allergic rhinitis and asthma. To date, the only treatment for food allergies has been to eliminate the offending food from the diet. In recent years, a number of studies have been published regarding desensitization or tolerance induction to food, particularly to cow' milk and egg, as an alternative treatment in patients who have not developed spontaneous tolerance. This is a review of the different studies of induction of tolerance with different type of foods and protocols. Oral induction of tolerance appears to be effective in induced short-term desensitization and to be quite safe, but further research is needed using large, high- quality studies that investigate and assesses the long-term efficacy, safety and cost-effectiveness of the induction of oral tolerance.

Overweight and obesity are major public health concerns with approximately 32% and 17% of U.S. children aged 2 - 19 being classified as overweight or obese, respectively. While the cause of overweight and obesity is multifactorial, changes in eating habits and physical activity patterns have been proposed as contributing factors to the obesity epidemic. For example, the displacement of nutrient rich foods and beverages with non-nutrient dense items may be influencing childhood obesity. Many children do not consume the recommended servings of the Food Groups to Encourage, i.e. low-fat and fat-free dairy foods, fruits, vegetables, and whole grains identified by the 2005 Dietary Guidelines for Americans which results in low intakes of calcium, potassium, fiber, magnesium, and vitamin E. While attention has focused primarily on reducing energy intake and/or increasing energy expenditure for weight maintenance, a promising beneficial role for dairy products in weight management has emerged. Most research has focused on adults, but there is evidence in children and adolescents indicating either a beneficial or neutral effect of dairy food consumption on body weight or body composition. The current review provides and assessment of the scientific evidence on the effects of dairy food consumption on body weight and body composition in children and adolescents.

Enhanced oxidation of branched-chain amino acids (BCAA; valine, leucine and isoleucine) in skeletal muscle is a typical metabolic alteration associated with activated synthesis of glutamine and development of muscle wasting in cachectic illness. The paper demonstrates that the rates of BCAA transamination and decarboxylation in skeletal muscle respond rapidly to changes in BCAA and glutamine availability. Enhanced BCAA availability increases BCAA oxidation and glutamine synthesis, while enhanced availability of glutamine suppresses BCAA oxidation. In physiological conditions, this enables compensation in alterations of amount and composition of food in order to keep optimal levels of BCAA and glutamine in the body. In cachectic illness, enhanced availability of BCAA (resulting mainly from activated proteolysis) and decreased availability of glutamine (resulting from its enhanced release by muscle) account significantly for activated BCAA oxidation and glutamine synthesis in muscle. The clinical importance of the opposite effect of BCAA and glutamine supplementation on BCAA oxidation in the treatment of muscle wasting disorders should be elucidated.

A total of 48 samples of ready to-eat salads (RTE), containing different varieties of salads, of different brands sold in Italy, were purchased from several supermarkets, during period 2008-2009. This study was performed to determine whether microbial contamination, and in particular pathogenic bacteria, such as Listeria monocytogenes, were present in these food products. Samples were examined for mesophilic aerobic counts, yeasts and moulds, total and fecal coliforms, and presumptive Listeria monocytogenes counts. Results showed that, in general, the highest microorganism counts were associated with samples containing grated carrot (6.3 Log cfu g-1 of aerobic mesophilic microorganisms; 4.6 Log cfu g-1 of yeast and moulds; 2.8 Log cfu g-1 of total coliforms), while the lowest counts were, generally, associated with samples containing lettuce (2.8 Log cfu g-1 of aerobic mesophilic microorganisms; 2.3 Log cfu g-1 of yeast and moulds; 2.3 Log cfu g-1 of total coliforms). Of all the samples analyzed, only three (6 %) harboured L. monocytogenes.

Seeds of four fenugreek lines cultivated in Alberta and one commercially available fenugreek seed were investigated for anatomical features, nutrient composition, sapogenins and galactomannans. Seeds of all lines had similar anatomical features as assessed by SEM. Contents (%, w/w) of crude lipids, crude proteins, minerals, soluble fiber and insoluble fiber were 7-10%, 26-32%, 3%, 16-21%, and 26-32%. Fatty acid and amino acid profiles were similar in seeds of all lines. Sapogenins were present at levels < 0.5% (w/w) with diosgenin being the predominant species. Galactomannans comprised a substantial proportion of the seed weight (23-37%). Seeds were milled and sieved to separate the outer seed layer (seed coat/aleurone/endosperm) from the inner seed (cotyledon + axis). The majority of galactomannans (85%) were located in the outer seed layer, and recovery of galactomannans from whole seeds, the outer seed layer, and the inner seed were 46%, 89%, and 47%, respectively. Relative to the total seed galactomannan content, galactomannan extraction yields from whole seeds, the outer seed layer, and the inner seed were 16%, 14%, and 7%. Galactomannan purity in gum extracted from whole seeds or the outer layer fraction exceeded 90%, whereas it was only 35% in the inner seed fraction. The data suggest that aqueous extraction of the outer seed layer may be a viable means of extracting high levels of purified galactomannans from fenugreek.