Decreased hardness of dietary fiber-rich foods by the enzyme-infusion method

A novel technique is reported for softening plant tissues while retaining their shape by impregnating them with macerating enzymes under reduced pressure after defrosting the frozen plants. Samples were removed immediately from the enzyme solution after the freeze-infusion treatment, and the hardness was measured. Six enzymes and three enzymes were respectively chosen from 18 commercial enzymes for softening burdock roots and bamboo shoots. The tissue degradation due to impregnation of the tissues with the enzymes and the reaction time were investigated. Burdock roots and bamboo shoots were progressively softened during the reaction: the hardness reached 1.0 x 10(4) N/m(2) or less. The water-soluble dietary fiber contents increased as a result of the freeze-infusion treatment. This softening technique, which retained the food shape, could enhance the production of food products for elderly persons and those under nursing care. Foods produced by this method can replace current minced and liquid dietary components.     

Chitosan-based polyelectrolyte complexes: A review

This review focuses on the formation of polyelectrolyte chitosan complexes with biologically active compounds and the prospects of use thereof. The possibility of obtaining low-molecular-weight, water-soluble batches of chitosan, which differ in their degree of acetylation, is discussed, with emphasis on their use for binding nucleic acids into complexes.Translated from Prikladnaya Biokhimiya i Mikrobiologiya, Vol. 41, No. 1, 2005, pp. 9–16.Original Russian Text Copyright © 2005 by Ilina, Varlamov.     

Factors determining dietary intakes of heterocyclic amines in cooked foods.

The identification of heterocyclic amines (HCAs) in cooked foods has focused attention on the potential health effects from their consumption in the diet. Recent studies have estimated daily dietary intakes of HCAs that vary 10-fold and implicated different cooked meats as the prime source of HCAs in the diet. These varied estimates can be attributed to the different dietary assessment methods used in these studies, as well as the different levels of HCAs ascribed to the most commonly consumed cooked meats. Epidemiological studies utilizing information on dietary practice and food intake have found higher risks for several cancers among individuals consuming the highest levels of HCAs. These studies have highlighted the importance of using information on cooking methods in addition to food intake to accurately estimate dietary exposure to HCAs.     

Experimental perspective on fallback foods and dietary adaptations in early hominins

The robust jaws and large, thick-enameled molars of the Plio–Pleistocene hominins Australopithecus and Paranthropus have long been interpreted as adaptations for hard-object feeding. Recent studies of dental microwear indicate that only Paranthropus robustus regularly ate hard items, suggesting that the dentognathic anatomy of other australopiths reflects rare, seasonal exploitation of hard fallback foods. Here, we show that hard-object feeding cannot explain the extreme morphology of Paranthropus boisei. Rather, analysis of long-term dietary plasticity in an animal model suggests year-round reliance on tough foods requiring prolonged postcanine processing in P. boisei. Increased consumption of such items may have marked the earlier transition from Ardipithecus to Australopithecus, with routine hard-object feeding in P. robustus representing a novel behaviour.     

Diet and sperm quality: Nutrients,foods and dietary patterns

Human semen quality has declined worldwide in the last 40 years, by some accounts as much as 50–60%, causing serious concerns and implications for human fertility. Even though it has been shown to be a worldwide problem, this decrease is more pronounced in developed and industrialized countries, pointing to changes in modifiable lifestyle factors (e.g. unhealthy diets, lifestyles, and pollution) as the main causes. Studies investigating the relation between diet and semen quality can be classified into three groups; studies assessing the association between semen quality and 1) nutrients, dietary supplements and antioxidants, 2) food, and 3) dietary patterns. The present narrative review provides a wide-ranging vision of the positive associations and effects of diet on sperm quality. Although the picture of the relationship between diet and sperm quality and fertility is far from complete, a number of broad conclusions have emerged. First, increased intake of selenium and zinc, omega-3 (ω-3) fatty acids, CoenzymeQ10 (CoQ10) and carnitine supplements have been positively related to sperm quality. In terms of food groups, vegetables, fruits, nuts and whole cereals, all rich in fiber and antioxidants, and fish, seafood, shellfish, poultry, and low-fat dairy products have been positively associated with sperm quality. Finally, adherence to healthy dietary patterns is positively associated with sperm concentration and sperm motility.     

Chitosan-based polyelectrolyte complexes: a review

The review focuses on the formation of polyelectrolyte chitosan complexes with biologically active compounds and prospects of use thereof. The possibility of obtaining low-molecular-weight, water-soluble batches of chitosan, which differ in their degree of acetylation, is discussed, with emphasis on their use for binding nucleic acids into complexes.     

Chemopreventive effects of minor dietary constituents in common foods on human cancer cells

Epidemiological evidence has suggested that vegetables and fruits may have a role in cancer prevention. The aim of the present study was to examine the anti-proliferative activity of ten related pure compounds from common vegetables and fruits. Studies were conducted on a series of carcinoma cells derived from eight human organs. The results show that linalool possessed the strongest activity against nine carcinoma cells, and that baicalein and luteolin also exhibited a broad spectrum of anti-proliferative activities. Among them, linalool showed the strongest activity against carcinoma of the cervix (IC50: 0.37 microg/ml), stomach (IC50: 14.1 microg/ml), skin (IC50: 14.9 microg/ml), lung (IC50: 21.5 microg/ml) and bone (IC50: 21.7 microg/ml). As for the flavonoids, luteolin exhibited the strongest activity against carcinoma of the stomach (IC50: 7.1 microg/ml), cervix (IC50: 7.7 microg/ml), lung (IC50: 11.7 microg/ml) and bladder (IC50: 19.5 microg/ml), whereas baicalein possessed the strongest anti-proliferative activity against carcinoma of the cervix (IC50: 9.8 microg/ml), stomach (IC50: 16.1 microg/ml) and skin (IC50: 19.5 microg/ml). The present study indicates that linalool possessed the strongest activity against a broad spectrum of carcinoma cells, especially cervical carcinoma cells, suggesting that linalool and flavonoids are partially responsible for the cancer prevention of common vegetables and fruits.     

Adding monounsaturated fatty acids to a dietary portfolio of cholesterol-lowering foods in hypercholesterolemia

Background

Higher intake of monounsaturated fat may raise high-density lipoprotein (HDL) cholesterol without raising low-density lipoprotein (LDL) cholesterol. We tested whether increasing the monounsaturated fat content of a diet proven effective for lowering LDL cholesterol (dietary portfolio) also modified other risk factors for cardiovascular disease, specifically by increasing HDL cholesterol, lowering serum triglyceride and further reducing the ratio of total to HDL cholesterol.

Methods

Twenty-four patients with hyperlipidemia consumed a therapeutic diet very low in saturated fat for one month and were then randomly assigned to a dietary portfolio low or high in monounsaturated fatty acid for another month. We supplied participants’ food for the two-month period. Calorie intake was based on Harris–Benedict estimates for energy requirements.

Results

For patients who consumed the dietary portfolio high in monounsaturated fat, HDL cholesterol rose, whereas for those consuming the dietary portfolio low in monounsaturated fat, HDL cholesterol did not change. The 12.5% treatment difference was significant (0.12 mmol/L, 95% confidence interval [CI] 0.05 to 0.21, p = 0.003). The ratio of total to HDL cholesterol was reduced by 6.5% with the diet high in monounsaturated fat relative to the diet low in monounsaturated fat (−0.28, 95% CI −0.59 to −0.04, p = 0.025). Patients consuming the diet high in monounsaturated fat also had significantly higher concentrations of apolipoprotein AI, and their C-reactive protein was significantly lower. No treatment differences were seen for triglycerides, other lipids or body weight, and mean weight loss was similar for the diets high in monounsaturated fat (−0.8 kg) and low in monounsaturated fat (−1.2 kg).

Interpretation

Monounsaturated fat increased the effectiveness of a cholesterol-lowering dietary portfolio, despite statin-like reductions in LDL cholesterol. The potential benefits for cardiovascular risk were achieved through increases in HDL cholesterol, further reductions in the ratio of total to HDL cholesterol and reductions in C-reactive protein. (ClinicalTrials.gov trial register no. {"type":"clinical-trial","attrs":{"text":"NCT00430430","term_id":"NCT00430430"}}NCT00430430.)Strategies that combine cholesterol-lowering foods or food components such as viscous fibres and plant sterols have been recommended to enhance the effectiveness of therapeutic diets low in saturated fat and cholesterol.^1,2 Such dietary combinations (known as dietary portfolios) have resulted in substantial reductions in low-density lipoprotein (LDL) cholesterol³ and its apolipoprotein (apolipoprotein B), but the beneficial effects on high-density lipoprotein (HDL) cholesterol and its apolipoprotein (apolipoprotein AI) have been less apparent.⁴ Low concentrations of HDL cholesterol and apolipoprotein AI in the plasma and an elevated ratio of total to HDL cholesterol are recognized risk factors for cardiovascular disease.^5–9 Thus, dietary strategies that both lower total and LDL cholesterol and raise HDL cholesterol should have broad application. One method for increasing HDL cholesterol appears to be the use of monounsaturated fat, a key constituent of the Mediterranean diet, particularly when monounsaturated fat replaces dietary carbohydrates.^10,11 Furthermore, increased intake of monounsaturated fat, through increased consumption of nuts and vegetable oil, has been associated with a reduced incidence of cardiovascular disease in cohort studies.^12,13We compared the effect on serum lipids of substituting 13.0% of total calories as carbohydrate with monounsaturated fatty acid in a dietary portfolio that has previously been shown, under controlled conditions, to be effective in lowering LDL cholesterol (by 28%) and the ratio of total to HDL cholesterol (by 24%).³ These reductions are similar to those seen with lovastatin 20 mg/d taken with the control diet.³     

Chitosan-based coagulating agents for treatment of cheddar cheese whey

Chitosan-Polyanion (Chi-Pol) complexes were used as coagulating agents for treating Cheddar cheese whey. Complexation and coagulation time played a significant role in adsorption, whereas polymer concentration was significant only for chitosan-alginate complexes. Complexes of chitosan with alginate (ALG), pectin (PEC), and carrageenan (CAR) used at 30 mg complex/L whey showed turbidity reductions of 40-43% and 65-72% after 1 and 39 h, respectively. At 10 mg/L, the percent reduction in turbidity after 1 and 39 h were 35-39% and 61-64%, respectively. No significant differences in turbidity reduction (P > 0.05) were observed when using complexes at different Chi-Pol monomeric mixing ratios (MR) except for Chi-Alg at 30 mg/L, wherein reduction at 0.2 was higher than 0.8 MR. Also, UV-vis spectroscopy suggested the preference of this complex for the absorption of specific whey protein fractions. This study successfully demonstrated the effectiveness of Chi-Pol complexes in flocculation of suspended solid wastes in cheese whey with over 70% protein recovery.     

Early weaning programs rats to have a dietary preference for fat and palatable foods in adulthood

The objective of this work was to study the effect of early weaning on alimentary preference for the macronutrients protein, carbohydrate and fat in adult rats. Male Wistar rat pups were weaned by separation from the mother at 15 (D15) or 30 (D30) days old. Body weight and food intake were measured every 30 days until pups were 150 days old. At 110 days of age, the alimentary preference was evaluated for 1 h on 3 consecutive days. At 120 days of age, the palatable diet test was conducted during 3 consecutive 24-h periods. Body weight and food intake were not altered, but early weaning in rats induced an alimentary preference to fat and hyperphagia of a palatable diet. In conclusion, early weaning, although did not modify body weight or basal food intake, promoted an increased preference for palatable and fatty foods. This demonstrates that early weaning is not capable of promoting perceptible alterations of alimentary behavior under normal laboratory conditions. However, in the presence of a stimulating factor such as a choice of nutrients or a palatable diet, a possible latent effect on dietary preferences may become apparent. Over the long term, this preference for foods with high caloric density can lead to obesity and metabolic perturbations.     

工程化软骨支架用壳聚糖基仿生材料研究进展

从材料学的视角介绍了壳聚糖在软骨组织工程支架中的应用情况,分析和总结了现阶段壳聚糖基仿生支架材料的特点,提出用数学和统计的方法研究仿生三维织物的构想,以期明确值得关注的研究方向.     

Aluminium, calcium and magnesium content of Hungarian foods and dietary intakes by children aged 3.9 and 14 years

The Al, Ca and Mg content of 147 kinds of foods and beverages, representing a large proportion of the Hungarian diet, has been determined using replicate samples. Dietary intakes of these minerals by 67 kindergarten children and 139 schoolchildren have been assessed. The richest sources of Al were: parsley, celery, gherkins, barley-malt; of Ca: dairy products, celery, parsley, savoy; of Mg: dried beans and peas, parsley, dill, maize-flour, rice, gherkins, chocolate. Flavouring agents (e.g. salt, pepper, paprika, caraway-seed) had very high concentrations of all three minerals and poppy-seeds that of Ca and Mg. The presence of bone-dust or fragments elevated the Ca content of some meats and cooked dishes. The main source of dietary intake of all three minerals was food; as opposed to F, the contribution of water-borne Al, Ca and Mg was negligible. Based on average values, the daily intake of all three minerals was satisfactory in both age groups. Mg intake was marginally below the recommended limit for a few children, but no signs of Mg deficiency were seen.     

Traditional fermented foods

For centuries, diverse plant and animal materials have been fermented by various bacteria, yeasts, and fungi to make excellent foods. The kinds of micro organisms used in traditional fermentation are restricted to a relatively few genera, including Aspergillus, Rhizopus, Mucor, Actinomucor, Monascus, Saccharomyces, Neurospora, Acetobacler, Bacillus, and Lactobacillus. The two principal advantages of food fermentations over other processes are to add flavor and to prevent spoilage. Fermented fish is a common food in the Orient and may have been the first product made by fermentation. Flavor is especially important in vegetable diets based on bland foods such as rice. Shoyu is the best, known oriental food fermentation, and it is very widely used as a flavoring agent. Be sides this fermentation, there are a large number of additional ones not so well known outside the Orient, whose products serve as seasoning or flavoring agents. Miso and natto are prepared from soybeans in Japan. Sufu is a cheese like product made from soybean milk in China. Tempeh and ontjom are Indonesian foods prepared from soybeans and peanuts, respectively. These food fermentations are discussed with emphasis on how they are produced and the flavor formed.     

生物技术与食品

现代生物技术是以生命科学为基础,利用生物或其组织部份的特性和功能,设计构建具有预期性状的新物种或新品系,以及与工程原理相结合进行加工生产,为社会提供商品和服务的综合性技术体系。生物技术已经被运用了许多个世纪,传统上它曾被集中地用于生产新种类的食品,如面包、奶酪、啤酒、葡萄酒以及酱油、米酒和发酵的奶制品。食品工业在过去几十年里发生了些什么变化?首先,世界范围的人口结构发生了重要变化,老年社会的形成,65岁以上的人口增加了,这些人需要符合营养结构的及可以立即食用的产品。其次,家庭规模的减小意味着对小包装食品的需求…     

Prebiotics in foods

A wealth of information has been gathered over the past 15 years on prebiotics through experimental, animal and human studies, with the aim to understand the mechanism of actions and elucidate their beneficial health effects to the human host. Significant amount of evidence exists for their ability to increase the bioavailability of minerals and stimulate the immune system, although there is less clear evidence so far for their prophylactic or therapeutic role in gastrointestinal infections. Moreover, the effect of the food delivery vehicle on the efficacy of prebiotics is an area that has been hardly investigated. Besides their beneficial effects, prebiotics influence the textural and organoleptic properties of the food products, such as dairy and baked products. To do this however, they need to be stable during food processing, in particular under conditions of high temperature and low pH.     

Enterococci from foods

Enterococci have recently emerged as nosocomial pathogens. Their ubiquitous nature determines their frequent finding in foods as contaminants. In addition, the notable resistance of enterococci to adverse environmental conditions explains their ability to colonise different ecological niches and their spreading within the food chain through contaminated animals and foods. Enterococci can also contaminate finished products, such as fermented foods and, for this reason, their presence in many foods (such as cheeses and fermented sausages) can only be limited but not completely eliminated using traditional processing technologies. Enterococci are low grade pathogens but their intrinsic resistance to many antibiotics and their acquisition of resistance to the few antibiotics available for treatment in clinical therapy, such as the glycopeptides, have led to difficulties and a search for new drugs and therapeutic options. Enterococci can cause food intoxication through production of biogenic amines and can be a reservoir for worrisome opportunistic infections and for virulence traits. Clearly, there is no consensus on the acceptance of their presence in foodstuffs and their role as primary pathogens is still a question mark. In this review, the following topics will be covered: (i) emergence of the enterococci as human pathogens due to the presence of virulence factors such as the production of adhesins and aggregation substances, or the production of biogenic amines in fermented foods; (ii) their presence in foods; (iii) their involvement in food-borne illnesses; (iv) the presence, selection and spreading of antibiotic-resistant enterococci as opportunistic pathogens in foods, with particular emphasis on vancomycin-resistant enterococci.     

Chitosan-based microcapsules containing grapefruit seed extract grafted onto cellulose fibers by a non-toxic procedure

A novel non-toxic procedure is described for the grafting of chitosan-based microcapsules containing grapefruit seed oil extract onto cellulose. The cellulose was previously UV-irradiated and then functionalized from an aqueous emulsion of the chitosan with the essential oil. The novel materials are readily attained with durable fragrance and enhanced antimicrobial properties. The incorporation of chitosan as determined from the elemental analyses data was 16.08 ± 0.29 mg/g of sample. Scanning electron microscopy (SEM) and gas chromatography-mass spectroscopy (GC-MS) provided further evidence for the successful attachment of chitosan microcapsules containing the essential oil to the treated cellulose fibers. The materials thus produced displayed 100% inhibition of Escherichia coli and Staphylococcus epidermidis up to 48 h of incubation. Inhibition of bacteria by the essential oil was also evaluated at several concentrations.     

Chitosan-based hybrid immobilization in bienzymatic reactions and its application to the production of laminaribiose

A hybrid-immobilization method was developed to improve the long-term stability of laminaribiose phosphorylase immobilized on epoxy supports Sepabeads EC-EP/S. Entrapment in chitosan retained all of the enzyme activity depending on the amount of entrapped solid materials and increased half-life by a factor of 10–94.4 h. No enzyme activity loss was determined during 12 times reuse. The immobilization method is also applicable to sucrose phosphorylase immobilized on Sepabeads EC-EP/S. Up to 31.9 g/L laminaribiose were produced in bienzymatic batch experiments with reaction-integrated product separation by adsorption on zeolites.