As an overwhelmingly major component, the role of water in food is reviewed comprehensively from a physicochemical view point. In aqueous solutions, the deviation of water activity, aw, from the ideal solution was proved to arise mainly from solute hydration. In macromolecule solutions, interactions among macromolecules were affected by aw and also the balance between the hydration and cosolute-binding of macromolecules. The ice fraction, which affects various properties of frozen food, was described well by a two-parameter equation with the initial freezing temperature and the unfrozen water content. In crystallization, ice crystal growth is extensively driven by heat transfer, causing unstable dendritic growth that is limited by water diffusion. Methods for freeze concentration were classified into four categories, and equilibrium suspension crystallization and progressive freeze-concentration were compared as possible alternatives in practice. Some chemical reactions are accelerated in the frozen state. This mechanism was explained by the concentration effect with freezing. In the freezing of cells, the freeze-induced dehydration rates of plant cells were much lower than those of microorganisms and animal cells, which seemed to explain the lower freeze-tolerance of plant cells and tissues.
Extrusion is a versatile and state-of-art technology and provides enormous opportunity for modifying the functionality of food materials for improved digestibility and high sensory quality. With considerable previous research on cereal based products, the current focus has now shifted towards millets and pulses for enhancing nutritional and functional quality for high-end consumer. The present review highlights the current advances made in development of cereal, millet and pulse based extruded products. In addition, the current trends in use of extruded flours as novel green ingredients as hydrocolloids, fat replacers and for developing gluten-free, phenolic-rich, low-glycemic and functional foods has also been reviewed.
The effects of different ultrasonic powers, times and temperatures on the physicochemical properties of bovine serum albumin (BSA)–galactose conjugates were investigated. SDS-PAGE and size exclusion chromatography analysis indicated that BSA–galactose conjugates gave a higher molecular weight than native BSA. The BSA–galactose conjugates prepared through ultrasonic pretreatment had higher degree of graft (DG) value, surface hydrophobicity (H0), emulsifying, foaming property and denaturation temperatures (Td) as compared to native BSA and untreated BSA-galactose conjugates. The highest DG, H0, and emulsifying ability index were obtained in ultrasonic time, power and temperature of 10 min, 150 W/cm2, and 45°C, respectively. The maximum foaming property and Td were detected in the sample ultrasonicated at 150 W/cm2 for 10 min at 35°C. From this, we conclude that increased DG and H0 in BSA–galactose conjugates were correlated with the improved emulsifying property and foaming capacity. Overall, ultrasonic pretreatment combined with glycation has great positive effects on the physiochemical properties of BSA.
The aim of this study was to optimize amounts of chickpea sourdough (A) and instant active dry yeast (B) in bread formulation and to evaluate the potential use of chickpea sourdough in bread production by examining various quality parameters. An experimental design suggested by Response Surface Methodology was used. The bread produced according to the optimized model (OBrd) was compared with control bread (CBrd) in terms of several quality parameters. According to the optimization results, optimum levels of usage were 59.06 g for A and 3.39 g for B. Smaller and more homogeneous pore structures were obtained in bread (OBrd) texture by the use of chickpea sourdough according to the image analysis. The bread also acquired sour, sweetish and acceptable sensory profiles. Physicochemical properties and antioxidant activity were also improved by the use of chickpea sourdough.
The drying curves of pullulan, alginate, and blend films at 40, 50 and 60°C were investigated using gravimetric methods. Several mathematical models available in the literature were fitted to the experimental data. The Midilli- Kucuk model satisfactorily described drying kinetics of tested films with the highest R2 and the lowest RMSE, SSE values. For the pullulan-alginate samples, the drying rate increased monotonically with the increasing drying temperature and alginate content of resulting films. However, the heat and mass transfer coefficients of all samples were affected by the temperature during the constant-rate period. Among the temperature tested, effective diffusion coefficient values of tested samples increased progressively with increasing alginate content during the first falling-rate period, whereas this tendency was not observed during the second. Information obtained from this study is essential for designing equipment and optimizing drying parameters for pullulan-alginate edible films.
Apigenin is a bioactive ingredient found in many vegetables and herbs, especially parsley (Petroselinum crispum L.). It was successfully extracted at high yields from parsley leaves using supercritical carbon dioxide (SCCO2) without co-solvent. A strong correlation was especially apparent at high SCCO2 density. The amount of extracted apigenin was well correlated with the difference in solubility parameters between the solvent (SCCO2) and the solute (apigenin). A lower energy requirement for extraction resulted in a greater amount of extracted apigenin. Various pre-treatments of parsley leaves (particle size, drying method and hot-water soaking of the samples) were examined to maximize the amount of extracted apigenin. Soaking in hot-water and then freeze-drying of parsley leaves was an optimal pre-treatment to realize the maximum amount of extracted apigenin.
Edible oil was the important component of food and easily oxygenated. To inhibit lipid peroxidation, adding synthetic antioxidants were commonly used. However, the safety of the synthetic antioxidants was doubted and it was advised to develop the safe, efficient and natural antioxidant. Grape polyphenols was the important secondary metabolites of grape. In the paper, the antioxidant activities of polyphenolic extracts from grape pomace on seven types of Chinese edible oils was studied. By measuring the peroxide value (POV) and acid value (AV) of edible oils under different conditions to show the antioxidant activities of grape polyphenols. The results showed that when adding amounts of grape polyphenols were 0.02%, the antioxidant effects were obvious. Compared with BHT and TBHQ, the antioxidant activity of grape polyphenols had a better effect on sesame oil. And there was a synergy between grape polyphenols and Vitamin C, and the opimum ratio was 1:4.
Cardamom is added to Arabic coffee the most popular drink in Saudi Arabia, and used as an food additives in many dishes in Saudi kitchen, the mycological profile and mycotoxin contaminated of cardamom selling in different markets in western regio. (KSA) was studied. Using morphological criteria and internal transcribed space (ITS) region sequencing, 23 species belonged to 11 fungal genera were identified from 80 cardamom samples collected from the western region of Saudi Arabia. Aspergillus was the most common genus, followed by Penicillium and Cladosporium then Mucor. Total aflatoxins (AFs) was the predominant mycotoxins contaminating almost 67.5% of cardamom samples. While ochratoxin A (OTA) was found in 47.5% of the samples notably, 36.3% of them were contaminated with both AFs and OTA. The mean concentration of AFs and OTA in cardamom samples ranged from 42.7 to 164.7 ppb and from 30 to 78 ppb, respectively. Total aflatoxins and ochratoxin A potentials of the collected isolates of Aspergillus flavus, A. parasiticus, Aspergillus niger, A. ochraceous, Penicillium citrinum and P. verrucosum were detected. The species-specific primers for A. flavus (FLA1 and FLA2) and A. niger (ITS1 and NIG) were used to detect directly the contaminations of cardamom samples.
A simple, rapid and efficient method for the determination of picoxystrobin in watermelon ecosystem was established and validated via QuEChERS (quick, easy cheap, effective, rugged and safe) method using rapid resolution liquid chromatography tandem mass spectrometry (RRLC-MS/MS). The average recoveries (n=5) of picoxystrobin in three matrix at three fortification levels ranged from 89.4% to 102.6%. The limits of detection (LODs) were lower than 1.28×10−4 mg L−1. The limits of quantification (LOQs) were 0.001 mg kg−1 for watermelon flesh (whole watermelon) and 0.005 mg kg−1 for soil. The half-life of picoxystrobin of whole watermelon (soil) in Shandong and Anhui were 1.43 (4.18) days and 3.71 (17.32) days, respectively. The picoxystrobin terminal residues in watermelon were lower than 0.001 mg kg−1 under the recommended dosages, which were far below the maximum residue limit (MRL) set by China (0.05 mg kg−1). These obtained data not only provide scientific information about safety estimation of picoxystrobin in watermelon and the kinetics of dissipation, but also facilitate trade exportation of watermelon for China.
Rice flour of the rice cultivar “Mizuhochikara” is suitable for making gluten-free bread without additives such as hydrocolloids or enzymes, but the bread becomes firm more rapidly than wheat bread. The firming rate of rice bread can be reduced by partially replacing the rice flour with sweet potato flour. Herein, when the replacement ratio or β-amylase activity in sweet potato flour was higher, the firming rate was lower. Rice bread made by 5% replacement of rice flour with sweet potato flour with the highest β-amylase activity had a firming rate that was more than three times slower than that of rice bread without replacement. The replacement of more than 5% of rice flour by sweet potato flour produced inferior shaped bread. Therefore, replacing up to 5% of rice flour with sweet potato flour with high β-amylase activity is a better way to reduce the firming rate of gluten-free bread.
This work addresses how granulated sugars with different melting points from two different refineries affect the taste of cooked food. Candied sweets and caramel sauces were prepared using the two types of granulated sugars. According to sensory evaluation, the candies and caramel sauces prepared by heating the wet sugar crystals, which remained undissolved in the solution, showed different tastes. This was confirmed by the color difference analysis and HPLC analysis of these two caramel sauces. However, the caramel sauces prepared from aqueous solutions of the sugars were not significantly different from each other in flavor. These results suggest that granulated sugars with different heating characteristics may have different crystal structures. During cooking, in which the sugar crystals are heated without being completely dissolved, the heating and melting characteristics of the sugars should be taken into consideration.
Previously, we reported that 4-week enzymatically synthesized glycogen (ESG) supplementation reduced lipid accumulation in diet-induced obese rats. The aim of this study was to investigate the effects of long-term dietary ESG supplementation on lipid metabolism of diet-induced obese mice. Male C57BL/6NCr mice were fed a control or a high-fat diet containing 0%, 10%, or 20% ESG for 15 weeks. In the high-fat diet groups, ESG showed significant suppressive effect on adipose tissue weight. Supplementation of ESG decreased plasma cholesterol and liver lipid levels. Although, ESG substantially increased fecal lipid, ESG did not affect lipid metabolism related gene expression. In control groups ESG increased body temperature and plasma NO, although the effects were not observed in high-fat groups. In the test of single administration, ESG significantly suppressed lipid absorption. In this study, we confirmed the anti-obese effect of ESG. It is mainly due to inhibition of lipid absorption by ESG.
Our previous study indicated that certain commercially available proteases inhibit biofilm formation by cariogenic streptococci. Natto made from soybeans cultured with Bacillus subtilis natto contains an abundance of proteolytic enzymes. In this study, we investigated the correlation between the protease activity of extracts from 36 commercially available natto products and the inhibition of biofilm formation. The biofilm inhibitory effect was found to correlate with the level of protease activity in the natto extracts, without reducing the viable cell numbers. The natto extract markedly inhibited the production of a water-insoluble glucan by Streptococcus mutans, which is the main agent involved in the formation of biofilm by cariogenic streptococci. The characteristics of the protease present in the extract were similar to those of nattokinase. Our results indicate that the protease activity exhibited by extracts of the Japanese fermented food natto reduces the risk of caries by inhibiting biofilm formation.
Eleven mycelial strains of the genus Hericium were isolated to investigate the variability in milk-clotting activity and ability to coagulate ultra-high-temperature pasteurized milk (UHT-milk) of their crude enzymes. As well, the antifungal activity of cheese prepared using the crude enzymes was assessed. Based on sequence analysis of ITS-5.8S ribosomal DNA, 8 strains were identified as H. erinaceus, 2 as H. abietis, and 1 as Hericium sp. Notable differences were observed among the species and within strains in terms of milk-clotting activity of the crude enzyme preparation. The UHT-milk coagulation ability was detected in 5 strains of H. erinaceus and showed no correlation with the potency of milk-clotting activity. Furthermore, all cheese samples prepared from low-temperature pasteurized milk using the crude enzymes from the 8 strains of H. erinaceus and ripened for 30 days at 13°C showed growth inhibitory activity toward Aspergillus niger NBRC 105649. Thus, the crude enzyme preparation from H. erinaceus may be useful for cheese production.
This work evaluated the influence of extrusion on the physicochemical properties of oat polysaccharides and its improvement in flour dough quality. Solubility, solvent retention capacity, and water binding capacity of extruded oat bran polysaccharides (EOPs) were effectively improved when compared to normal oat bran polysaccharides (NOPS), whereas the gelation temperature markedly decreased. The EOP solution revealed strong viscoelasticity. Moreover, the extensibility and gumminess of EOP-added dough were significantly improved when compared to blank dough. Therefore, EOPs are highly potential for use as new functional ingredients in food.
Natto is a major functional food in Japan. γ-Polyglutamic acid (γ-PGA) is one of the main components of Natto, and beneficial effects of γ-PGA have been reported. We tested the hypothesis that γ-PGA alleviates metabolic syndrome in KK-Ay/TaJcl male mice. These mice were fed a diet containing 0.5% of γ-PGA or a control diet for 28 days. Visceral fat was significantly smaller in the PGA group than in the CON group. The amounts of lipids in feces (dry weight) sampled on the final day of the experiment and cecal Lactobacillus counts were significantly greater in the PGA group than in the CON group. Cecal Prevotella counts tended to be higher in the PGA group. These results suggest that dietary γ-PGA affects the cecal microbiota and ameliorates accumulation of visceral fat in the KK-Ay/TaJcl mouse model of type 2 diabetes mellitus.
Pasta samples boiled for different times and mixed with tomato sauce were physically and chemically evaluated to determine the factors affecting the suitability of boiled pasta with tomato sauce for eating. Physical properties of the pasta boiled for the shortest time changed greatly when sauce was added. The texture of the pasta boiled for the longest time was soft, because the core lacked a non-gelatinized region. In a force–strain curve, the change in the force after the breaking point of the pasta boiled for the shortest time was the largest after sauce addition. The T2 values and chlorine distribution of pasta samples showed that the amount of penetration of the sauce ingredients to the core of the pasta boiled for the shortest time was less than that of the pasta boiled for the longest time. These results suggest that small changes in the physical properties after the sauce addition, sufficient penetration of the sauce ingredients to the core, and the presence of a non-gelatinized region at the core are critical factors affecting the suitability of boiled pasta with tomato sauce for eating.
Pomegranate juice (PJ) has higher polyphenol content and antioxidative activity than any other fruit juice. We used a pomegranate polyphenol concentrate (PPC) from pomegranate juice and investigated its inhibitory effects and mechanism of action using a contact hypersensitivity (CHS) test. The ear swelling induced by 2,4-dinitrofluorobenzene (DNFB) was inhibited in the PPC-treated group compared to that in the control group. Antigen-specific IgG1 was lower in the PPC-treated group than in the control group; however, serum antigen-specific IgG2a was not different. More splenic IL-10-producing and IFN-γ-/IL-4-producing CD4+ T cells were observed in the PPC-treated group than in the control group. These results suggested that PPC afforded protection against CHS and IgG1 production by increasing IL-10-producing CD4+ T cell numbers.
We examined changes in water-soluble pectin (WSP) and dilute hydrochloric acid soluble pectin (HSP) contents of tea leaves, and pectin content of tea infusions in the roasting process during refined tea manufacturing by crop season. In all crop seasons, WSP content in tea leaves increased with roasting temperature. HSP content was almost constant or increased with roasting temperature by crop season. Changes in pectin content of tea infusions by roasting temperature were proportional to or lagged slightly behind WSP content changes of tea leaves in all crop seasons. In all crop seasons, the molecular weight (MW) distribution of both WSP in tea leaves and pectin in tea infusions was biased toward the lower-MW range with increasing roasting temperature. In parallel, major peaks in the MW distribution of pectin in tea infusions shifted to the lower-MW range in all crop seasons. It was postulated that β-elimination degradation was involved in WSP production from water-insoluble forms of pectin in HSP and the degradation of WSP itself during the roasting process.