The stability of mineral elements in rice is not only related to genotype and environmental factors, it is also related to processing precision. In this study, japonica rice from Jiansanjiang, Heilongjiang province, China, was analyzed and divided into five processing grades. Analysis of elements in the rice using inductively coupled plasma-mass spectrometry (ICP-MS) indicated that Na, Mg, Al, K, Ca, Cr, Mn, Fe, Co, Cu, Zn, Rb, Sr and Ba contents differed due to the influence of different processing precision. By removing elements which were significantly changed by processing, we were able to establish a more stable origin traceability model of rice, with an average discrimination accuracy of 96.1% and cross validation accuracy of 93.9%. Results from our study aid in improving the stability of the geographical origin traceability model, thereby making it suitable to be used for rice with various processing precisions.
A large amount of bread crust is generated in the production of sandwiches and other bread products which, is not sufficiently used as food. If this crust can be reused effectively in the bread making process, it can add value, reduce waste, and improve the flavor and texture of bread. However, an excess amount of gelatinized starch (GS) in crust inhibits gluten network formation in bread dough and greatly decreases bread making qualities (BMQs). In this study, we investigated the optimal amount of two bakery enzymes, α-amylase (AM) and hemicellulase (HC), that can be added to improve the BMQs of crust-added dough. The optimal amounts of the enzymes were determined using response surface methodology and Solver, an Excel add-in software. The results showed that BMQs, specific loaf volume (SLV), gas retention of dough (GRD) and staling of dough and bread with added crust gel (CG) and optimal amounts of AM and HC were drastically improved compared to those without additional enzymes. It was concluded that response surface methodology and Solver are effective methods to easily determine the optimal amounts of the two enzymes to add to CG-supplemented dough to obtain high SLV and desirable texture, flavor and taste. The only negative aspect is poor bread color.
The effects of zein coating on the total bacterial count, total volatile base nitrogen and histamine in high (5.0 log CFU/g) and low (2.0 log CFU/g) spiked roasted rabbit legs stored at different temperature (−20, 4, 20, and 37 °C) were studied. At 37 °C, the preservation effect of zein film was not obvious. If storage temperature was below 37 °C, zein coating inhibited microbial breeding and histamine production significantly. Freezing (−20 °C) is an effective way to inhibit the growth of microorganisms and histamine accumulation. However, microbes breed rapidly when samples defrosted at 20 °C. Compared to samples without coating, samples coated zein can store for 48 h at room temperature, and the total volatile base nitrogen is still below the threshold (< 30 mg/100 g). These results can provide a reference for the production of high quality meat related products with zein coating.
This paper addresses the quality classification of various types of jujube. That is, for a given type of jujube, we consider how to achieve a highly precise classification of the various dimensions of high-quality jujube, shorten the classification time, improve the efficiency and make it feasible for practical application. The current methods rarely reach the above requirements. To this end, we propose the MI-net (multi-channel weighting and information aggregation) model, which enables the convolutional neural network to learn the aggregate information of the multi-channel feature maps. The proposed model is able to obtain different levels of features and better utilize the channel characteristics, which enhances the discriminative power and generalization ability. The experimental results show that the classification of the full jujube, dried jujube, cracked jujube and broken jujube achieves accuracies of 99.64%, 99.78%, 99.93% and 98.97%, respectively. The overall classification and recognition accuracy rate reaches 99.62%.
The aim of this study was to evaluate metabolism of Saccharomyces boulardii during milk fermentation. Skimmed milk was fortified with Wheat Grain juice (4% v/v), inoculated with an active culture of S. boulardii, and fermented for 12 h at 37 °C. Yeast metabolism affected by either the small contents of glucose or unavailability if the fermented milk was free of Wheat Grain juice. Fortification of milk with Wheat Grain juice provided the glucose and fructose for S. boulardii resulted in increased cells growth to some extent. Channeling such sugars by S. boulardii for its metabolism, however, was not enough to make any significant effect on ethanol yield (0.27 mg/100 g) rather than lactic (0.15–0.64 g/100 mL) and acetic acids (0.094–0.18 mg/g). The marginal decline of reducing sugars contents in the formulations due to incapability of S. boulardii to form free glucose from milk lactose's or Wheat Grain starch's maybe address the low production of ethanol, as well the pH developments (≤5.33).
Almost all processing residue from tankan juice production are wasted; therefore, we developed a vinegar extract derived from this residue. Vinegar extract was produced using the direct pulverizing method, which was characterized by a yellow color and had the highest aroma scale, low bitterness, and various components, such as polyphenols. Vinegar extracts produced by other methods, such as the stirring and soaking methods, were not as yellow as that produced using the direct pulverizing method, yet they included a group of functional components, polymethoxyflavones, such as nobiletin as well as monoterpene alcohols that are classed as sweet floral, such as linalool. However, vinegar extract produced by the soaking method contained few monoterpenes, such as limonene that do not have a unique citrus flavor, and may be more favorable for use in drinks and seasonings. Therefore, depending upon the desired final product, any of these vinegar extracts may be used.
A mathematical model to research airflow distributions and heat transmission in two different packages was developed. The precooling characteristics of two packaging designs were evaluated in terms of cooling time, uniformity, apple quality and energy consumption undergoing forced air cooling. The numerical model was verified by a detailed comparison of predicted and measured results. The modelling results revealed heterogeneous cooling airflow patterns in current ventilated carton, which results in the heterogeneity of product temperature. While in new package design, especially at first layer, the seven eighths cooling time (SECT) was about three times less than the current package, and the mass loss rate was reduced by 66.4%. In addition, the chilling injury rate and maximum temperature deviation for both apple layers were decreased to 17% and ∼2.7 °C, respectively. The value of energy consumption (EC) was reduced by 65.1%.
Transglutaminase-catalyzed reactions can be used widely to modify the functional properties of food proteins, biopharmaceuticals and in tissue engineering. Streptomyces mobaraensis is important for industrial fermentation because of its rapid, low-cost growth and easy cultivation. We cloned the transglutaminase (TGase) gene from S. mobaraensis; the gene was 1224-bp (65.22% G+C), encoding 407 amino acids. Then, expression vector pL99-T was constructed by cloning the TGase gene into plasmid pL99. pL99-T was introduced into S. mobaraensis using conjugation and protoplast transformation method, respectively. We observed TGase activity of 8.68 U/mL in the transformant SMP-12, 5.88-fold that of the original strain (1.26 U/mL); moreover, the expression of TGase protein was higher in the transformant than in the original strain. These results suggest that directed overexpression of TGase can effectively enhance the TGase activity and protein production by S. mobaraensis. This method of enhanced expression of active TGase in S. mobaraensis may be valuable for industrial applications.
Japanese mint (Mentha arvensis) is a widely used herb for culinary, fragrant, and medicinal applications. In this study, useful substances were obtained from Japanese mint leaves by extraction using subcritical water (180 to 260 °C). The characteristics of the mint extracts, including carbohydrates, proteins, and phenolic content, as well as 2′,2′-diphenyl-1-picryhydrazyl (DPPH) radical scavenging activity were investigated. The highest carbohydrate content was obtained at 180 °C, while the highest amount of protein was obtained at 200 °C. A linear relationship was observed between the phenolic content and DPPH radical scavenging activity. Oligosaccharide was the most abundant sugar in the extracts, as determined by high performance liquid chromatography analysis. The presence of apocynin, a potent non-steroidal anti-inflammatory drug, was identified by gas chromatography-mass spectrometry and its content showed an exponential increase as the temperature was increased from 180 to 260 °C. This study provides practical information for applications of Japanese mint.
Satsuma mandarin (Citrus Unshiu MARC.), which is a widely consumed citrus fruit in Japan, contains flavanone glycosides such as hesperidin and narirutin. Flavanone glycoside contents were higher in discarded unripe Satsuma mandarin (USM) than in edible ripe ones. Sprague-Dawley rats were fed diets containing USM at the levels of 2.5, 5.0 or 10.0% for 4 weeks. USM feeding at 2.5 or 5.0% did not affect serum and hepatic lipid levels. USM intake at the level of 10.0% significantly lowered serum concentrations of triglycerides, free fatty acids, glucose, insulin, and leptin compared with the USM-free (control) diet. Hepatic triglyceride and cholesterol levels were also significantly lowered. In addition, hepatic enzyme activities related to lipogenesis, but not lipolysis, were significantly lowered. Fat excretion into feces was not affected by UMS feeding. These results suggested that feeding of discarded USM rich in flavanone glycosides showed hypolipidemic, especially hypotriglyceridemic effects, partly through the suppression of hepatic lipogenesis.
Sugarcane extract (Saccharum officinarum extract: SOE), a byproduct containing polyphenols obtained through the process of making raw sugar from sugarcane, exhibited an effect on the discoloration of salmon that suggests SOE inhibits lipid oxidation, which inhibits discoloration of carotenoid as a result. Therefore, we considered an in vitro evaluation method for inhibiting discoloration of carotenoid, and used this method to measure SOE's inhibitive effect on carotenoid discoloration. The results showed that the methylene chloride soluble portion (low-polarity fraction) had the strongest inhibitive effect. We then refined and isolated the components of the methylene chloride-soluble portion to obtain 13 known components and one new compound. Structural analysis revealed that the new compound is 3-[2-(β-D-glucopyranosyloxy)-4,6-dimethoxyphenyl]-1-(4-methoxyphenyl)-1-propanone, which is a glycoside of retrodihydrochalcone. The results suggest that, combined with the content and antioxidant effect of the isolated compounds, simulanol, a lignan, contributes most to inhibiting carotenoid discoloration through the methylene chloride-soluble portion in SOE.
To elucidate the effect of fat crystals and liquid fat on the bubble interface in whipped cream, we observed structural changes in fat globules and bubble interfaces caused by whipping using cryo-transmission electron microscopy. The results suggested that fat crystals formed lamellae at the fat globule interface, together with liquid fat at the center of the fat globules, which were dissociated from the fat globule under whipping. As whipping progressed, fat crystals fragmented and were adsorbed on the bubble interface, such that the area occupied by the fat crystals in the bubbles gradually increased. This behavior was presumed to contribute to the stability of whipped cream bubbles. Furthermore, liquid fat released from the fat globules was inferred to occupy gaps between the fat globules.
In this study, a milk-clotting enzyme was partially purified from the mycelium of Hericium erinaceum (H. erinaceum) by ammonium sulfate fractionation, ion-exchange chromatography and gel filtration. The enzyme was purified at approximately 60-fold from a crude enzyme solution with 0.3% recovery of the original activity. The partially purified enzyme was found to have a molecular weight of 36 kDa as determined by SDS-polyacrylamide gel electrophoresis (SDS-PAGE), and 30 kDa by gel filtration high performance liquid chromatography. The proteolysis of κ-casein by the partially purified enzyme from H. erinaceum was studied with SDS-PAGE and reverse-phase high performance liquid chromatography. The results revealed that degradation of κ-casein occurred with the partially purified enzyme from H. erinaceum, and that it might be similar to the degradation observed with chymosin.
These results indicate that a chymosin-like protease is present in the mycelium of H. erinaceum.
Cooking rice mixed with barley, called Mugimeshi in Japanese, is one of the most common multi-grain cooking styles in Japan. While we reported the localization of barley β-amylases during Mugimeshi cooking, that of rice enzymes remains unknown. In this study, we investigated the localization of rice α-glucosidase using an immunoblot technique while barley and rice were soaked in water and heated together to 60 °C. Surprisingly, rice α-glucosidase of Koshihikari cultivar was found not only in rice grains and cooking water, but also in barley grains after barley and rice were soaked in water for an hour. Rice α-glucosidase of Nipponbare cultivar was, however, not released from rice grains into cooking water. In barley grains, the amount of rice α-glucosidase from Koshihikari was highest after the soaking step. These data clearly showed that rice α-glucosidase was translocated from rice grains into barley grains via cooking water during Mugimeshi cooking in some rice cultivars. This finding suggests that, in addition to barley enzymes, rice α-glucosidase contributes to barley starch degradation during Mugimeshi cooking.
Ginger rhizome contains a number of proteases that possess milk clotting activity. It has been revealed that ginger rhizome juice acts as a coagulant to form milk gels. In this study, we investigated the gel forming conditions of soymilk using ginger rhizome juice. Soymilk gels were prepared by incubating a mixture of soymilk (prepared at different conditions) and a lyophilized powder suspension of ginger rhizome juice at 60 °C for 60 min. The strength of soymilk gels increased when the raw soymilk was heated above 90 °C prior to mixing with the ginger rhizome juice. At a high gel strength, decomposition of the glycinin fraction in soymilk was observed with SDS-PAGE analysis. These results suggest that decomposition of the glycinin fraction in soymilk plays an important role in gel formation.