The effects of the pressurized hot water extraction (PHWE) parameters (extraction temperature: 100, 150 and 200°C and extraction time: 5, 10 and 15 min) on the total phenolic content and DPPH radical scavenging capacity of the kaffir lime (Citrus hystrix) fruit peel extracts were investigated. Both indices increased as the extraction temperature increased. The extraction time only slightly affected the values. This study also demonstrated that the PHWE produced extracts with a higher phenolic content and radical scavenging capacity than that obtained by a conventional extraction method (water and 60% methanol at 50°C, 1 h).
The long pepper (Capsicum annuum L. cv. 'Yalova Charleston') was stored in plastic film with various oxygen (O2) and carbon dioxide (CO2) permeabilities consisting of 7±1°C temperature and 90±5% relative humidity (RH). Physico-chemical changes were recorded on 0, 10, 20 and 30 days of storage. Weight loss was higher in pepper stored under normal atmosphere (NA) compared to modified atmosphere packaging (MAP). Initial total soluble solids of 4.20% increased to 5.27% in NA. The acidity and ascorbic acid contents of peppers decreased during storage. The highest values were recorded at the end of storage from the fruit stored under PP (polypropylene). Changes in fruit color at the end of storage proceeded more slowly in the treated fruit. Total chlorophyll values exhibited significant decline in the fruits subjected to NA. However, the chlorophyll content in the fruits subjected to PP was low. The color values obtained from fruits supported the chlorophyll findings. At the end of the study, 35μ PP packaging material gave the best result at the end of 30 day-storage with respect to the parameters evaluated in the study. Therefore, especially 35μ PP treatment was effective with regard to delaying the maturity along the storage and fruit quality in peppers.
Effects of protein isolate prepared from hyacinth bean (Lablab purpureus (L.) Sweet) seeds on cake characteristics were studied. The addition of up to 1% of the protein isolate from hyacinth bean seeds could improve the baking properties of the cake. The volume development and specific volume of the cake with 1% protein isolate were 206.0%, and 2.63 ml/g, whereas those of the control were 160.3% and 2.17 ml/g. Isolate additions of up to 1% softened the cake, as indicated by decreases in texture values, i.e., 184, 112, 100 and 89 g of force for the control, 0.5, 0.75 and 1.0% protein isolate, respectively. However, when more than 1% protein isolate was added, the cake quality tended to decrease compared with that at 1%. Moreover, the more protein isolate was added, the more vivid the colour and the lower the staling rate. Therefore, the protein isolate from hyacinth beans merits further assessment as a practical food additive.
Alcohol insoluble residue of Japanese pepper fruit (Zanthoxylum piperitum DC.) is an underutilized by-product of antioxidants extraction. The content of the residue was 77.7 g/100 g dry material and the major component was sugars (57.3 g/100 g AIR). In addition, approximately one-fifth of total sugars were uronic acid. In this study, pectins were extracted from the by-product by sequential extraction with various reagents, and the chemical compositions of the pectins were then compared. As a result of the compositional analysis, Fourier transform infrared spectroscopy and size-exclusion chromatography, pectins obtained with water, oxalate and cold dilute alkali were low methoxyl pectins while pectins obtained with hot dilute acid were high methoxyl pectins. In addition, the sugar compositional analysis revealed that the oxalate soluble pectin consisted mostly of galacturonic acid, indicating that it was a pectic acid.
Male mice (11 months old) were fed 5% lard, fish oil, or kazunoko (salted fish roe product) lipids for 4 months to investigate the effects of diet on plasma glucose and adipocytokines. Plasma glucose levels were significantly lower in the fish oil group than in the lard group and there was a non-significant tendency towards lower levels in the kazunoko lipid group. Plasma leptin and adiponectin levels were also significantly higher in fish oil group than in lard group and resistin levels were significantly lower in the kazunoko lipid group than the lard group, but not the fish oil group. The results suggest that kazunoko lipids might be effective as a dietary component in the prevention of coronary heart disease and diabetes even though the metabolic effects of kazunoko lipids were different from those of fish oil.
Soymilk was prepared by non-heated squeezing and then heated at various temperatures. For one-step heating, the precipitate produced by heating soymilk increased for heating at 70 and 80°C and was much less at 90°C or higher temperatures, showing that the dispersion stability of soymilk was dependent on the heating temperature. In the case of two-step heating (combinations of 115°C and a lower temperature), soymilk heated at 115°C in the first step and 70 or 80°C in the second step resulted in increased precipitation. Changes in protein surface hydrophobicity were considered to be related to the precipitate formation of soymilk heated at the two different temperatures, indicating the significance of heat denaturation and aggregate formation of proteins on the dispersion stability of soymilk.
The combined effects of pH, temperature, buffer/substrate ratio, time and enzyme concentration on nitrogen recovery (NR) from porcine hemoglobin, a by-product of industrial abattoirs, with Pancreatin and Flavourzyme® 500MG enzyme mixture were characterized. The effect of hydrolysis variables on NR was described through response surface analysis (RSA). The results showed that pH and time were the most important parameters and that the buffer/substrate ratio had less of an effect on NR. The mathematical model presented an optimum hydrolysis conditions were as follows: temperature, 50.4 °C; pH, 7.8; buffer/substrate (containing 33.1% protein) ratio (w/w), 1.4:1; time, 15.4h; and enzyme concentration, 2.0g/kg. The predicted NR value was 98.99%, and the actual value obtained was 97.69%. Molecular mass of recovered hydrolysates ranged from >15 kDa to free amino acid (<1 kDa). The admixture of enzyme had specificity for terminal a variety of hydrophobic amino acids which resulted in recovery of non-bitter hydrolysates from porcine hemoglobin.
Physico-chemical properties; amylose content, swelling power, pasting properties by Rapid Visco Analyzer (RVA), thermal properties by Differential Scanning Calorimeter (DSC), and enzymatic digestibility of starches isolated from 19 different Sri Lankan rice varieties were analyzed. Significant variation was shown in all the tested properties among tested varieties in which the amylose content varied from 16.0% to 34.7%. Amylose content appears to be the major factor controlling almost all physico-chemical properties of rice starch, as it showed significant correlations to all other properties tested. It correlated negatively to the peak and breakdown viscosities by RVA and enzyme digestibility but positively to all other tested properties. The peak and onset gelatinization temperatures and enzyme digestibility correlated to all properties except enthalpy for starch gelatinization. The peak and onset gelatinization temperatures, as well as the blue value, showed negative correlations to the peak and breakdown viscosities, indicating the importance of low amylose for easy starch pasting. According to our results, low amylose starches started to gelatinize at lower temperatures. During heating and cooling, such starch slurry showed higher peak and breakdown viscosities, but resulted in a softer gel. Low amylose starch was also easily digestible by enzymes. These properties are probably associated with the reduced compactness in the amorphous area of starch granules. Due to lower amylose in the amorphous area, loosely packed starch granules result in higher swelling power and disorganization with heating.
Soybean phospholipids are known to exhibit antioxidant effects on oils and fats. However, few studies have examined their antioxidant effects in vivo. In this study, we investigated the influence of dietary soybean phospholipids on fish fillet oxidation. For 4 weeks, we fed rainbow trout diets containing 0, 1.0, or 2.5% soybean phospholipids, of which the lipid content was adjusted with soybean oil. We compared oxidation stability in fillets after the feeding period. In the fillet of fish fed the soybean phospholipidcontaining diets, the thiobarbituric acid reactive substance (TBARS) level following an oxidation test was significantly inhibited compared to that in the fillet of fish fed a soybean oil-containing diet. Similarly, the syntheses of malondialdehyde (MDA) and 4-hydroxyalkenals (HAE) were significantly inhibited. These results suggest that the administration of soybean phospholipids improves the storage stability of fish fillet.
The mature leaves of Japanese ‘Saijo’ persimmon (Diospyros kaki Thunb.) are consumed as ingredients in health foods and teas. Levels of ascorbic acid and polyphenols were compared between the mature leaf (M-leaf), young shoot (T-shoot; cultured by water-soaking twigs grown the previous year) and adventitious shoot (A-shoot; obtained from orchard trees). The level of total ascorbic acid (T-AsA) was highest in M-leaves, and though the levels of polyphenols were high in M-leaf and A-shoot, they were remarkably low in T-shoot. Isoquercitrin and astragalin levels were highest in A-shoot, followed by M-leaf, and then T-shoot.
Soluble sugars, sugar alcohol, and organic acid contents in Actinidia fruits at the eating-ripe stage were determined in various genotypes using high-performance liquid chromatography: five A. deliciosa, seven A. chinensis, two A. rufa, eight A. arguta, and three interspecific hybrids. The main soluble sugars in A. deliciosa and A. rufa fruits were glucose and fructose, although sucrose was present in smaller amounts. In contrast, sucrose was the predominant sugar in A. arguta fruits, followed by fructose and glucose. Most Actinidia fruits tested here contained myo-inositol as a sugar alcohol component. In particular, myo-inositol contents in A. arguta fruits were 0.575–0.982 g/100 g fresh weight, which is the highest level among all foods. Regarding the organic acid component, citric and quinic acids predominated over malic acid in all Actinidia fruits tested. Compared to A. deliciosa and A. chinensis, the proportion of quinic acid was higher in A. rufa and lower in A. arguta.
A dedicated magnetic resonance imaging (MRI) apparatus that is small, lightweight, and usable in an ordinary research room was devised for developmental research and quality estimation of foods and agricultural products. The thawing processes of frozen margarine and meats were traced, the distributions of oils in adipose tissue (fat) and water in muscle tissue for pork and beef were distinctively visualised, the oil-accumulating tissues in seeds and the sticky materials on surface of fermented soybeans (natto) were characterised, and the three-dimensional organisation of the fine vasculature in fruits was visualised by the apparatus. The proton-specified MRI was easy to operate and provided well depicted images of internal structures, the distribution and mobility of water and oils, and susceptibility differences inside materials, demonstrating that the devised machine is useful for food and agricultural research.
The epimerization reaction of tea catechins was investigated at pH 5.5 and 120 °C in the absence/presence of cyclodextrins (CDs). In the absence of CDs, a considerable quantity (∼20%) of products originating from reactions other than the epimerization (“other products”) was formed during the epimerization of gallated catechins. In the case of (-)-EGCg, addition of β-CD to the reaction solution reduced the quantity of these other products to just a few percent, but other CDs with different cavity sizes had little effect. Generally, the addition of β-CD increased the ratio of non-epi type catechins, that is, [non-epi type catechin] / ([epi type catechin]+[non-epi type catechin]). Molecular orbital (MO) calculations using the PM3 method suggested that non-epi type catechins are more thermodynamically stable than their epitype counterparts, moving the equilibrium position in favor of non-epi type catechins in the epimerization process.
To elucidate the effects of simple processing on seaweed as food, several methods were applied to Undaria pinnatifida. In this study, 1) boiling in the NaCl solution or 2) soaking in acetic acid, 3) calcium lactate or 4) sodium gluconate solution were performed for U. pinnatifida. After processing, dietary fiber content, breaking strength and molecular weight of extracted alginate were measured. Breaking strengths and insoluble dietary fiber contents decreased as boiling time increased. Breaking strength of U. pinnatifida after calcium lactate treatment was higher than that for sodium gluconate treatment. Molecular weight of alginate was not affected by processing, excepting heating treatment. Our results indicate that processing methods other than heating primarily affect the texture of seaweed products.
The effect of vespa amino acid mixture solution (VAAM), a unique amino acid mixture identified in the saliva of the larva of a species of hornet endemic to Japan on adipocyte lipolysis was investigated in order to verify the possible mechanisms underlying the regulatory effect of VAAM on in vivo fat metabolism. VAAM significantly increased basal leptin secretion and lipolysis without an increase in cAMP production. However, VAAM failed to amplify either isoproterenol or dibutylyl cAMP-stimulated lipolysis, which is increased intracellular cAMP productions, accompanied by a significant decrease in leptin secretion. These results suggest that VAAM may enhance basal lipolysis independent of cAMP productions, but is dependant on leptin secretion from adipocytes themselves, at least in part.
The physiological effects of red Welsh onion were examined and compared with those of white Welsh onion. Male 6-week-old spontaneously hypertensive rat (SHR) was fed a control diet or diets high in fat and sucrose (HFS) with or without 5 % Welsh onion (red or white variety) for 4 weeks. A significant effect to suppress the increase in the blood pressure and the increase in the lipids in plasma and liver was observed in rats fed the red, but not white, Welsh onion compared to the rats fed the HFS diets. Red and white Welsh onion was effective to suppress the increase in the lipid peroxides in plasma, and in liver in case of white Welsh onion. The activity of antioxidant enzymes was downregulated by feeding the red and white Welsh onion. These results suggest that, although the antioxidant activity of red Welsh onion is weaker than the white one, antioxidant activity together with hypolipidemic effect of red Welsh onion might work favorably to suppress the increase in blood pressure. Detection of flavonoids, especially quercetin, and anthocyanins suggests that these compounds might be physiologically active components in red Welsh onion.
The objective of the study was to analyze the influence of antioxidant components on antioxidant activity of dehydrated green leafy vegetables (GLV), namely, Amaranthus sp., Centella asiatica, Murraya koenigii and Trigonella feonum graecum. The edible portion of the GLV was chemically treated, steam blanched, oven dried and analyzed for antioxidant components and antioxidant activity. Multiple regression analysis was done to test for the relationship between antioxidant activity and the antioxidant components. The ascorbic acid, total carotene, β-carotene and total polyphenol content (tannic acid equivalents) of the GLV ranged between 1.94 – 8.63, 12.13 – 29.8, 2.63 – 4.24 and 637.50 – 1170.83 mg/100g respectively. The total antioxidant activity was highest in Trigonella feonum graecum and the least in Amaranthus sp. The GLV exhibited varied levels of antioxidant activity as analyzed by 1,1-diphenyl-2-picryl hydrazyl (free radical scavenger), reducing power and ferrous ion chelating activity at different concentrations of the extract, which were significantly different. Multiple regression analysis showed that the relationship of (i) total antioxidant activity, (ii) free radical scavenging activity and (iii) reducing power, each with antioxidant components in dehydrated GLV, was statistically significant.