The social phenomenon of the growing number of elderly patients with bone disease or fractures attributable to osteoporosis is closely associated with an increase in the number of bedridden elderly, and is a causative factor in the rise of the total cost of national health care. We hypothesized that the excellent effects of cow’s milk on bone health might not be limited to an abundance of calcium, and investigated substances in milk that regulate bone remodeling to enhance bone mineral density. We successfully identified the “milk basic protein” (MBP) component of milk, which has a direct effect on the strengthening on bones. MBP stimulated proliferation of osteoblasts involved in bone formation and collagen production and also suppressed the activity of osteoclasts involved in bone resorption. The supplementation of some daily foods with MBP has made it possible to maintain properly balanced bone remodeling and to increase bone mineral density in human volunteers. MBP is expected to be a functional component in helping to maintain human bone health.
Near infrared (NIR) spectroscopy was investigated as a method for nondestructive measurement of specific gravity of potato. A total of 250 potatoes of three cultivars, Irish-Cobbler, May-Queen and Kita-akari, were used as experiment samples. The NIR spectra (700-1100nm) of potato samples were acquired by the interactance method and partial least square (PLS) regression analysis was used to develop a predictive model for specific gravity. As a result, the model gave relatively good predictions of the specific gravity, with a correlation coefficient of 0.94 and standard error of prediction of 0.0044g/cm3. The results show the potential of the NIR technique as a means for nondestructive measurement of specific gravity of potato with reasonable accuracy.
To elucidate the physicochemical properties of silk protein, we studied the effects of calcium chloride and ethanol on the gelation of fibroin. Fibroin was treated with 5.0M calcium chloride in water (Ca/W) or 5.0M calcium chloride in 20% (v/v) ethanol (Ca/Et) and the rheological properties of colloidal fibroin were investigated. The Ca/W-treatment promoted an increased rate of gelation and gave higher gel strength than the Ca/Et-treatment. The maximum gel strengths of Ca/W- and Ca/Et- treated fibroins were obtained at pH 7.0 and pH 5.5, respectively. Scanning electron micrographs showed that the Ca/W-treated fibroin gel had a more developed three-dimensional molecular network than the Ca/Et-treated gel. Further, FT-IR spectra suggested that Ca/W-treated fibroin has more of a β-structure than Ca/Et-treated one in colloidal conditions. This study indicated that the use of calcium chloride alone was more beneficial to the gelation of fibroin than combined use with ethanol.
Construction of a predictive model for hygenic management of liquid foods was attempted by investigating the effects and interactions of storage conditions on the aerobic growth kinetics of Bacillus amyloliquefaciens in a soup product. The Gompertz curves were generated from the experimental data obtained under three temperatures (298 to 310K) in combination with four levels of inoculation (5.32×10-3 to 5.32×10-6g·L-1) and five levels of ethanol concentration (2.7 to 4.7g·L-1). The microbial growth kinetic analysis disclosed that ethanol was effective for prolonging lag phase duration of the growth in a processed soy sauce. The Gompertz function in combination with nonlinear equations generated by stepwise regression analysis was suitable for predicting the growth of organisms. The lag phase duration was about 18h longer than the quality guarantee period of a soup product containing a perceptible amount of contaminant organisms.
The effects of supplementation of high protease activity wheat (Triticum aestivum) flour due to bug (Eurygaster spp.) damage on characteristics of wheat flour extrudates were investigated. Different proportions of high protease activity flour (HPAF) were blended with wheat flour (0, 10, 20, 30 and 40%) and extruded with a twin-screw Brabender laboratory extruder (Model CTSE-V) at two different barrel temperatures (140°C and 160°C). The obtained extrudates were tested for extrusion quality parameters. Significant differences were observed between two barrel temperatures (140°C and 160°C) in terms of water absorption index (WAI), specific mechanical energy (SME), bulk density (BD) and color (redness) values of the extrudates (p<0.05). Statistical analysis showed that addition of HPAF had significant effect on SME, WAI and WSI (water solubility index) values of extruded samples at 140°C. At higher process temperatures (160°C), SME, color, WAI and WSI values of the extrudates were significantly affected by the addition levels of HPAF. At both process temperatures, a significant decrease and a significant increase were observed in BD and ER (expansion ratio) values of the extrudates, respectively. These results suggested HPAF had positive effects on some quality parameters (BD, ER, WAI and WSI) of the extrudates in the proportions examined.
Three agricultural products, carrot, broccoli and potato tissue, were osmotically dehydrated by immersion in 50% (w/w) sucrose solution and their rheological properties were measured before and after freezing-thawing-rehydration. Although the dynamic elasticity and viscosity became smaller after freezing-thawing as compared to the fresh sample, the osmotically dehydrated sample showed much higher retention of rheological properties than the untreated sample with the exception of the potato sample. In measurement of complex impedance, the radius of the Cole-Cole arc, an index of the intactness of cell plasma membrane, showed good correlations with the rheological properties for carrot and broccoli. The amount of drip from the cell tissue was also compared among various treatments. The osmotically dehydrated sample showed much less drip than the untreated sample after freezing-thawing-rehydration. Under an optical microscope, the cell structure seemed to show less injury for the osmotically dehydrated sample than the untreated sample. These results indicate that osmotic dehydrofreezing protects the cell structure, in particular the cell plasma membrane, against freezing injury to give reduced softening after freezing-thawing.
The combined effect of mild heating and pressurization on germination and inactivation of Bacillus subtilis spores was investigated. The spore count decreased remarkably at 60°C+80MPa in glucose broth as opposed to phosphate buffer. These results suggested that the spores germinated due to pressure and germination-inducing components in the glucose broth, and that the germinated spores were then inactivated by mild heating. The induction of germination started at 10MPa at 40°C or 20MPa at 60°C with the number of spores decreasing by two log-cycles in one hour. The relationship between the logarithm of spore number and pressure became linear in the pressure range of 50-300MPa. The germination ratio was 0.95log-cycles 100MPa at 40°C or 0.82log-cycles/100MPa at 60°C for half an hour in glucose broth.
To obtain the quantitative and qualitative data available for estimating the intake of carotenoids from fruits in Japan, carotenoids were analyzed with reversed phase high-performance liquid chromatography (HPLC). Ten carotenoids were examined in 75 raw fruits and 15 processed fruits, all of which were harvested or purchased in Japan. Phytoene was detected in 58 of 90 fruit samples ; ζ-carotene, in 50 of 90 ; lycopene, in 13 of 90 ; α-carotene, in 18 of 90 ; lutein, in 56 of 90 ; β-carotene, in 80 of 90 ; β-cryptoxanthin, in 68 of 90 ; zeaxanthin, in 58 of 90 ; all-trans-violaxanthin, in 55 of 90 ; and 9-cis-violaxanthin, in 47 of 90 samples. Citrus fruits of the mandarin type (Satsuma mandarin and its hybrids, such as tangor) were rich in β-cryptoxanthin, β-carotene, all-trans-violaxanthin, and 9-cis-violaxanthin ; ‘Star ruby’ grapefruit in lycopene ; loquat, Japanese persimmon, and peach in β-cryptoxanthin, β-carotene, all-trans-violaxanthin, and 9-cis-violaxanthin ; mango in β-carotene, all-trans-violaxanthin, and 9-cis-violaxanthin ; acerolas in phytoene ; passion fruits in ζ-carotene. Carotenoid levels in common fruits, such as apple, grape, lemon, pear, strawberry, kiwifruit, cherry, pineapple, and banana, were low.
Chemical properties of and the influence of ripening on “Mission” variety virgin olive oil cultivated in Japan were investigated. Olives were harvested every 10 days from October 25 to December 25, 2001 and the oil was extracted. Oil content of olives increased with fruit ripening, but at a lower level than that of other varieties in Europe. Oleic acid content was 75-79%, a medium level compared to other varieties in Europe. Total phenols of olives decreased with ripening. This fact may cause a decrease in the oxidative stability of the olive oil.
The effects of polyglycerol mono-fatty acid esters (PGMFEs) on dough properties and baking were investigated using six PGMFEs with saturated fatty acid moieties (octanoic, decanoic, lauric, myristic, palmitic, and stearic acids). The addition of the PGMFEs (0.5% w/w of flour) to dough significantly increased its resistance, retention of the generated gas, and the volume of bread compared to loaves baked with the addition of monoglycerides and the control. These effects increased with a decrease in the chain length of the fatty acid moiety of the PGMFEs. Microscopic observation of the fermented dough with the PGMFEs showed that the gluten matrix became thick and that most of the starch granules were sufficiently covered with the gluten matrix as compared with the control. Also, addition of the PGMFEs with palmitic or stearic acid moieties retarded firmness in bread like that of bread baked with monoglycerides. These results indicated that the addition of PGMFEs as dough-conditioners promoted gluten formation and retarded the firming of bread by acting as a softener.
Japanese green teas are produced by blending different materials and there are cases of discrepancy between the contents and the label of the product. Therefore, a technique for identifying tea cultivars among product contents is strongly required. A simple CTAB (Cetyl trimethyl ammonium bromide) extraction method with a short time pre-incubation yielded DNA is suitable for cultivar identification by CAPS (cleaved amplified polymorphic sequence) analysis. The extracted DNA was analyzed with seven CAPS markers to identify cultivars.
Soy glycinin was hydrolyzed by pepsin under controlled conditions. The emulsifying activity of the hydrolysates was found to be higher than that of glycinin. Fractionation of the peptides was performed in order to determine which peptides in the hydrolysates contributed to the enhanced emulsifying activity. A peptide fragment from an acidic subunit of glycinin A1a, corresponding to residues 209-275, was purified and was found to have a higher emulsifying activity at pH 4.0 than that of the original hydrolysate. Based on the hydropathic index, it is expected that the peptide possesses amphiphilic structure.
Fluorescence spectroscopic properties of honey and cane sugar syrup were investigated in order to explore the use of optical techniques for detection of adulteration of honey with cane sugar syrup. Measurements showed that while the major contributor to the fluorescence of cane sugar syrup is the reduced form of nicotinamide adenine dinucleotide, the fluorescence of honey is dominated by flavins. The difference in the synchronous luminescence spectra of honey and cane sugar syrup could be used to monitor adulteration of honey by cane sugar syrup.
The volatile compounds of kidney beans and soybeans were analysed by gas chromatography mass spectrometry (GC-MS) and proton transfer reaction mass spectrometry (PTR-MS). Fingerprint PTR-MS spectra of the kidney beans and soybeans showed similarities but also quantitative differences, with soybeans generally presenting higher intensities. Fifty-one compounds were identified by gas chromatography mass spectrometry, 39 in the kidney beans and 29 in the soybeans. Dynamic model-mouth/PTR-MS analysis revealed four masses predominant in both types of beans, m/z 33, 45, 59 and 73, which likely originate from methanol, ethanol, 2-propanone, and 2-butanone, respectively. The two beans differed significantly in the headspace concentrations of the masses m/z 33 and m/z 59 at various time points, with both higher in the soybeans. The four masses were released at fairly linear rates. The correlation coefficients of the concentration vs. time profile were in the range 0.874-0.992 under mouth conditions. Principal component analysis revealed that high release rates of the masses m/z 33, 59 and 73 correlated with the soybeans, whereas mass m/z 45 correlated well with the kidney beans. As a result of the quantitative differences, the proportions of the four masses differed between the two beans. For both types of beans their proportions also changed during the course of release.
Intestinal mucosal immunity is very important to the body’s defense system and can be affected by extrinsic factors such as bacteria and food components. In the present report we assessed the intestinal immunomodulatory activity of Feijoa sellowiana Berg (feijoa), a tropical fruit expected to become widely popular in Japan. We examined the effects of the aqueous extract from feijoa and the in vitro-digested feijoa on the secretion of IL-7 and TGF-β from Caco-2 cells that are used as in vitro models of intestinal epithelium. We found that both the aqueous extract and the in vitro-digested feijoa suppressed the secretion of TGF-β by Caco-2 cells. These results suggest that the continued intake of feijoa may induce a decrease in TGF-β concentrations in intestinal lamina propria, which may in turn cause suppressions of oral tolerance and disorders of mucosal homeostasis. Moreover, the polyphenols from feijoa appear to be involved in the suppressing effect of feijoa on TGF-β secretion by intestinal epithelium.
The present study deals with the effects of 10 fruits, 27 spices and 14 herbs on α-glucosidase activities for the purpose of developing therapeutic diets for diabetes. The glycemic indices (GI) of fruits and spices were also examined. All fruits were found to inhibit α-glucosidase. Apple and pineapple reduced GI to less than 100 on average, though no statistical siginificances were found. Fourteen raw and 14 cooked spices inhibited α-glucosidase. Cooked spices generally exceeded raw spices in inhibitory effects, and 4 herbs were found to inhibit α-glucosidase. No significant correlation was found between GIs and α-glucosidase-inihibiting ability of fruits. Of the cooked spices, mustard paste and nutmeg reduced GI among the subjects on average though no statistical siginificances were found. Unlike fruits, no significant correlations between GI and inhibiting ability in spices were observed.
Polyphenol oxidase was purified to homogeneity from Japanese wheat (Triticum aestivum cv. Tohoku 198) bran, using 4-methylcatechol as a substrate. The enzyme was purified 1670-fold with a recovery of 0.175% by alkalization, ammonium sulfate precipitation, anion exchange chromatography, hydrophobic chromatography and gel filtration chromatography. The molecular mass was estimated to be 35kDa and 40kDa by gel filtration chromatography and SDS-PAGE, respectively. The N-terminal amino acid sequence matched well with the internal sequences of other plant PPOs. The pH optima for the purified enzyme and the crude enzyme were 4.5 and 5.3, respectively. The purified enzyme was stable in the range of pH 6.5-7.5 at 4°C for 24hr. The purified enzyme was stable after heat treatment at 60°C for 10min. The purified enzyme oxidized L-tyrosine, pyrocatechol, 4-methylcatechol, L-DOPA, chlorogenic acid, (+)-catechin and (-)-epicatechin. The Km values of the purified enzyme for 4-methylcatechol and L-DOPA were 3.3mM and 8.3mM, respectively. The purified enzyme was strongly inhibited by dietyldithiocarbamate, thiourea, sodium azide, cystein, idoacetic acid, sodium fluoride, trans-cinnamic acid, p-coumaric acid, ferulic acid and vanillic acid. The KI value of the purified enzyme for ferulic acid was 108μM.
To assess the potential utilization of shrimp waste, shrimp chitin (SC) and shrimp chitin hydrolysate (SCH) were prepared from black tiger (Penaeus monodon), endeavour (Metapenaeus endeavouri) and giant freshwater (Macrobrachium rosenbergii) prawns. Effect of SC and SCH on the state of water and denaturation of lizard fish (Saurida wanieso) myofibrillar protein (Mf) at concentrations of 5% (dry weight/wet weight) were assessed based on water activity (Aw) and changes in Mf Ca-ATPase activity during dehydration. The effect was compared with untreated Mf (control) and Mf containing glucose. The Aw of Mf for each SCH was remarkably lower than the Mf with SC and control. The Mf with SCH showed a remarkably high level of inactivated Ca-ATPase activity, followed by Mf with SC and the control. Mf with glucose showed slightly higher inactivated Ca-ATPase activity than SCH, reaching Aw levels of 0.65, before rapidly decreasing. These findings revealed that SCH contributed to the retardation effect on dehydration-induced denaturation of Mf by stabilizing hydrated water molecules surrounding the Mf.
[Objective] The objective is to examine the effectiveness of heating process of sweet potato with sub-critical water to produce more antioxidant activity and cytotoxic and apoptosis induction activities on human promyelocytic leukemia HL-60 cells. [Methods and Results] Sweet potato steamed at 95°C was treated with sub-critical water at 200, 230, 250, 275 and 300°C, and the extracts, referred to as A, B, C, D and E, respectively, were obtained. The antioxidant activity was low in the steamed potato (extract S). After heating by the sub-critical water treatment, the extracts showed a markedly strong antioxidant activity and high amount of phenolic content. The antioxidant activity was in the order, E,D>>C>B>A and showed a good relationship with the amounts of phenolic content (r=0.95). The extracts showed a strong cytotoxic effect on HL-60 cells in the order, E,D>>C>B>A. Moreover, the cytotoxic activity of the extracts A and B was found to be mediated through apoptosis induction on this cell. [Conclusion] Sub-critical water treatment of sweet potato greatly promoted its antioxidant activity, cytotoxic and apoptosis induction activities on HL-60, demonstrating that this new technique could be a promising approach to promote functionality of foods.
Milkfish consumption and the effects on the proximate composition and docosahexaenoic acid (DHA) level of three cooking methods (Paksiw, Sinigang and fried) used to prepare milkfish were determined. Total moisture content, crude fat, crude protein and the total ash of the dishes were analyzed. Fatty acid methyl esters (FAMEs) were analyzed through gas chromatography. Results showed that milkfish is eaten once to twice a week by Filipino households. Proximate analysis revealed that Paksiw had the highest moisture content, and Sinigang had the highest crude fat content. Sinigang had a significantly lower crude protein content compared to raw fish, fried fish had the highest crude protein on a wet basis and Paksiw on a dry basis. The DHA level for Paksiw was not significantly different from raw milkfish, but DHA level for Sinigang and fried milkfish were significantly different from the raw sample. Different cooking methods can thus cause changes in the proximate composition and DHA content of milkfish.
Differences in the aromas of steamed green teas are due to the cultivars, the climate and the production process. We compare the volatile compounds found in steamed green tea of the same cultivar (cv. Yabukita (Camellia sinensis var. sinensis)) but produced in different places (Saitama, Shizuoka, Mie, Nara, Kyoto, Saga and Miyazaki prefectures). A total of 75 volatile compounds were identified by GC and GC/MS. The results showed observed differences in the quantities of these compounds. Principal component analysis (PCA) was performed for the GC data to investigate the relationship between green teas from different places. Each green tea was found to contain certain characteristic compounds.
The effect of 15h, 300ppm calcium hypochlorite soaking on microbial quality of mung seeds and sprouts was investigated. The extended chlorine soaking did not completely eliminate the microflora of the seeds but significantly reduced microbial proliferation rates during storage. Generally, microbial counts of the chlorine-soaked seeds were significantly lower than that of the control. Total plate count (TPC), lactic acid bacteria (LAB) and total coliform (TCC) populations of the seeds continuously increased during sprouting and sprout storage at 4.0°C, except for the yeast and mold counts (YMC) which increased during sprouting but decreased through the refrigerated storage. A significant decrease in the TPC of sprouts from chlorine-soaked seeds was observed after the 4th day of storage. Escherichia coli was not detected throughout the sprouting and storage periods. Salmonella was not isolated from the extended chlorine-soaked seeds, but was detected after the sprouting period.