Effects Of Food Components Research Articles

Effect of ecological factors on the inhibitory spectrum and activity of bacteriocins

The effect of food components and ecological factors on the activities of nisin, sakacin P and curvacin A was evaluated. Lactobacillus curvatus, Listeria innocua, Salmonella and Escherichia coli including E. coli O157:H7 were used as target organisms. Lecithin, casein, and divalent cations were antagonists of the bacteriocins at 0.1%, 0.1% and 10 mmol l −1, respectively. A decrease in pH as well as the presence of EDTA, propyl-parabene or NaCl at concentrations of 0–1 mmol y −1, 0–0.16 g l −1, and 0–6% (w/w), respectively, increased the activity of all bacteriocins. These compounds as well as a pH<5.5 rendered the Gram-negative target organisms sensitive against bacteriocins. Of practical importance is the respective effect of NaCl at concentrations >5% which are achieved in fermentation and ripening processes, e.g. in production of fermented sausages. A characteristic response was observed for each of the bacteriocins. It is suggested that bacteriocins of lactic acid bacteria are effective against a wide range of microorganisms including E. coli O157:H7 if applied in combination with other preservative principles prevailing in foods.

Mumefural, citric acid derivative improving blood fluidity from fruit-juice concentrate of Japanese apricot (Prunus mume Sieb. et Zucc).

The effects of food components on blood fluidity were studied by in vitro assay using a dedicated microchannel instrument for model capillaries. We found that the fruit-juice concentrate of the Japanese apricot (Prunus mume Sieb. et Zucc), a traditional Japanese food, markedly improved the fluidity of human blood. Using HPLC, we isolated the active compounds and characterized them using UV, MS, IR, and NMR. They included a novel compound, 1-[5-(2-formylfuryl)methyl] dihydrogen 2-hydroxypropane-1,2, 3-tricarboxylate (mumefural), and a related compound, 5-hydroxymethyl-2-furfural (HMF). Mumefural markedly improved blood fluidity in all subjects, while HMF worked differently in different individuals. The flow rate of blood spiked with mumefural or HMF was compared to that of the two predominant organic acids in the fruit. Citric acid, malic acid, and furfuryl alcohol also improved fluidity in all subjects. The activity of P. mume is derived from not only artifacts produced during thermal processing, such as mumefural, but also from endogenous organic acids.

Functional food science and behaviour and psychological functions.

The impact of ingesting various foods on psychological and behavioural functions is a topic of both interest and concern to the general public. In this article, the scientific literature concerning demonstrated cause-and-effect relationships is reviewed, beginning with methodological considerations specific to the quantification of particular behaviours and psychological events. The essential function of food is to satisfy hunger and the need for essential nutrients. The contributions of macronutrients to appetite and satiety are described, as well as their impact on metabolism and energy balance. Functional properties of macronutrient substitutes (high-intensity sweeteners, fat replacers) and flavour enhancers are examined in relation to their contribution to hunger, satiety, and energy balance. The effects of foods and individual nutrients on the performance of diverse psychomotor tasks are studied with consideration given to the various validated quantitative tools used to assess behaviour. The effects of food components on activation, sedation, and affective states such as dysphoria are also reviewed, with special attention given to brain function and neuroactive substances such as serotonin and the endorphins. The case of hyperactivity in children is given special emphasis with reference to the potential influence of sugar and food additives. Safety issues related to food constituents and additives are discussed. Finally, a set of criteria is proposed for the evaluation and elaboration of studies in the behavioural and psychological fields, along with suggestions for future research.

Dissolution of Aluminium from Aluminium Foil into Foods and Effect of Food Components on the Dissolution

The dissolution of aluminium from aluminium foil into 21 acidic foods and 6 alkaline foods was investigated. In the case of acidic foods, the dissolution level after 30min at 95°C was 10.02-13.83μg/cm2 in Pon-su, Lemon-su and Umeboshi, 3.11-6.85μg/cm2 in Ringo-su, Kabosu-su and wine vinegar, 0.66-0.92μg/cm2 in juice and yogurt, and 0.20-3.59μg/cm2 in vinegar brewed from cereals.The dissolution level in all acidic foods was less than that in 4% acetic acid, while that of Kokumotsu-su was 1/200 of that in 4% acetic acid after 30min at 95°C.In the case of alkaline foods, the dissolution level after 30min at 95°C was 13.72-16.24μg/cm2 in Konnyaku, 88.03-107.4μg/cm2 in Shirataki, and 10.55-10.97μg/cm2 in Chinese noodles.The dissolution was enhanced by the addition of sodium chloride, but it was depressed by the presence of proteins, amino acids, sugar or cholesterol, The dissolution in 4% acetic acid in 30min at 95°C decreased to below 10% in the presence of protein or amino acids.

Decrease in Organic Solvent Extractable Ethion by Grapefruit Pectin during Processing

The effect of food components on pesticide residue was examined using citrus fruit often heated to make marmalade. Commercial grapefruit was peeled, and the parts were fractionated by extraction with several kinds of solvents (n-hexane, acetone, methanol, and water). The amount of organic solvent extractable ethion remaining after heating was smallest in the crude peel water extract. Purification of the water extract by deposition with methanol and dialysis produced a gel. The gel reduced the amount of several organophosphorus pesticides extracted by organic solvent during heating. From the IR spectra, the chief ingredient of the gel was considered to be pectin, which is contained in most plants. Thus, the pectin of grapefruit was considered to have masked organophosphorus pesticides from organic solvent extraction. Pectin is easily transuded from foodstuffs by cooking and appears to play a role in reducing the amount of pesticide extracted by organic solvents with heating. Keywords: Pesticide; food; comp...

Adaptive significance of amylase polymorphism in Drosophila--VI. Properties of two amylase variants and the effect of food components on amylase activity in Drosophila subobscura.

1. Properties of amylase from two D. subobscura strains homozygous for two different amylase variants (AmyS and AmyF) were determined. 2. Amylase of both strain adults showed a pH optimum of 7.8. 3. The AmyF enzyme showed a higher thermostability. 4. They differed in both maximum activity and Michaelis constant (Vmax of 6.25 and 3.45, Km of 0.7% and 0.42% starch for AmyS and AmyF, respectively). 5. The effect of different feeding conditions in amylase activity in the above Drosophila strains was also studied. Amylase activity was always detected but to a different level depending on diet composition.

食品に内在する消化酵素分泌情報の解明と動物消化管における情報認識機構

食品に内在する消化酵素分泌情報の解明と動物消化管における情報認識機構

Effects of food components and additives on the formation of nitrosamides.

The effects of food components and food additives on the formation of nitrosamides were studied. Citrate accelerated nitrosamide formation from nitrite and various precursors, such as ureas, urethanes, guanidines and amides. The accelerating effects of citrate on the formation of methylurea and ethylenethiourea were larger at higher pH values. The formation of most nitrosamides was not accelerated by thiocyanate, which is known to catalyze the formation of nitrosamines. Compounds having carboxyl groups tended to accelerate the nitrosation of methylurea. Nitrosation of methylurea was inhibited by thiols, polyphenols, alcohols, sorbic acid, dl-alpha-tocopherol etc., due to possibly competition for available nitrite.

でんぷんの物性に与える食品成分の影響 ＩＩＩ でんぷんゲルの強度に及ぼす油脂の影響

食用油脂である菜種油およびラードを馬鈴薯澱粉およびコーンスターチに対し10-150%添加し, 15%澱粉濃度付近のゲルについて, 膨潤, 糊化の状態, ゲル強度さらに低温保存時の影響について調べ次のことがわかった.1) 馬鈴薯澱粉では, 85℃, 30分の加熱処理で, 油脂添加により膨潤, 糊化が抑制された.2) ゴーンスターチでは, 油脂添加量が10-30%の範囲で, ゲル強度の上昇効果が認められた. 油脂の添加により, 澱粉の膨潤糊化が進んだためと考えられる.3) 油脂添加量が50%を超えると, 両澱粉ともゲル強度は低下した, 油脂の添加量が多くなると, ゲルの構築が阻害され, ゲル強度は弱くなるものと考えられる.以上の知見は, 油脂含量の多い加工食品, たとえばハンバーグ, シュウマイ, ギョウザなどに応用できると考えられる.

The functional significance of amylase polymorphism in Drosophila melanogaster V. The effect of food components on amylase and ?-glucosidase activity

The functional significance of amylase polymorphism in Drosophila melanogaster V. The effect of food components on amylase and ?-glucosidase activity

Studies on poisonous metals. VI. Effect of food components on transport of cadmium across rat small intestine in vitro.

The effect of various proteins and amino acids and of the extracts from some foods on the tissue accumulation and the transport of cadmium in the in vitro rat small inte stine was studied. The proteins and amino acids used decreased considerably the accumulation of cadmium in the intestinal tissue. Ovalbumin and glycinin decreased significantly the transport of cadmium. In contrast with such proteins, L-cysteine and L-histidine, which form relatively stable complexes with cadmium, increased the transport of the metal. However, other amino acids, which have a relatively weak affinity for cadmium, had little effect on the transport of the metal. The extracts from soybeans, ivory-shells, and oysters depressed remarkably the accumulation of cadmium in the intestinal tissue. The transport of cadmium considerably decreased by both extracts from soybeans and ivory-shells and, on the contrary, significantly promoted by the oyster extract.These results suggest that the transport of cadmium across the rat small intestine is considerably influenced by the food components such as proteins and amino acids.