Advanced Materials Research Vols. 554-556

Abstract: Scanning electron microscopy of samples showed that corn flour granules by fermented and wet-milling were angular, pentagonal or elliptical similar to native starches while samples with extruding and cooking were irregularly fibrous and large granules. Protein of samples with wet-milling exhibited an obvious DSC endotherm, To 85.81°C, Tp 92.95°C, Tc 101.73°C and ΔH 1.614J/g.While the fermented and extruded samples had no endotherm. Ultra-violet absorption spectrometry showed that absorbance of fermented and extruded samples increased and the λmax were slightly red shift. The λmax were 294nm, 297nm and 310nm for wet-milling , fermented and extruded flour, respectively. SDS-PAGE patterns of wet-milling flour contained four bands, fermented samples only three bands while extruded samples had same bands with dry-milling.

Abstract: Tripe (maodu) is a traditional food in china, it is a slaughter by-product of beef industry and it has significant economic value. Increasing the application of slaughter by-products (including tripe) has economic importance in beef industry and research on processing technology of tripe is one of the major directions, but this field is lack of research at home and abroad. This paper summaries the processing technology of tripe, introduces a new processing technique which increases the yield to 145%, discusses its influence on food safety and expects the application prospects in tripe industry.

Abstract: Strain Gluconacetobacter hansenii CGMCC1671 and Saccharomyces cerevisiae CGMCC1670 were applied to make traditional Kombucha with pure cultures to search for the optimum parameters of major factors affecting the yields and productivities of Bacterial cellulose (BC) in the beverage. Three culture factors were examined. The yields and productivities of BC and sugar consumed were measured after cultured statically for 22 days. After single factor test factors affecting the yields and productivities of BC have been optimized by response surface methodology (RSM). The quadratic polynomial regression equation reflecting BC yield and affecting factors was build up with Box-Behnken design principle. The optimal values of 10.37% inoculum, initial pH 4.96 and medium volume 77.13 mL in 250 mL flask were obtained with theoretical BC yield 300.093mg/g. BC yield of 279.579 mg/g was obtained with 6.84% deviation by validation test with the optimal parameters. The co-culture of pure strains of traditional Kombucha technique can be used to provide both high quality and high yield of BC in addition to producing high quality Kombucha beverage.

Abstract: To study the activating blood and hypolipidemic effects of black mulberry on aged rats, the aged rats were divided into 3 groups and fed with black mulberry fruit or juice respectively. The blood of rats in treatment groups and control group was collected and determined after 8 weeks treatment. The results showed that antioxidant enzymes SOD and GSH-Px were increased in both treatment groups. Na⁺-K⁺-ATPase activity, the primary membrane enzyme of rat erythrocytes, was increased when the aged rats were fed black mulberry fruit or juice. The high-density lipoprotein cholesterol (HDL-c) and the erythrocyte membrane fluidity in the blood of rats treated with juice and fruit were improved. Furthermore, mulberry treatment significantly decreased MDA content in the serum and erythrocytes total cholesterol (TC) of rats. The Anti-atherogenic indexes (AAI) were distinguishedly increased in both treatment groups(P<0.05). The results suggested that both the fruit and juice of black mulberry have beneficial effects including activating blood, hypolipidemic and anti-atherosolerosis.

Abstract: The open culture is a simple, low-cost way for microalage cultivation, and the great advantage of which is that it can be easily used for mass production. This culture system is primarily used for the alga that can survive under bad or extreme conditions. N. flagelliforme is a kind autotrophic alga having the property of alkali-resistance, which makes open culture of N. flagelliforme become possible. In this study, the cultivation of N.flagelliforme with an open, 60×40×30cm rectangular glass reactor was conducted. Firstly, the open culture of N.flagelliforme was carried on without new nutrient elements supplemented into pond intermittently. During the whole process of cultivation, the pH maintained at 8-9 in order to avoid the contamination of other green alga. At the end of the cultivation, the cell density reached 0.802 g•L^-1 and the exopolysaccharide concentration was 97mg•L^-1. Secondly, the fed-batch cultivation was employed to increase biomass and exopolysaccharide production. At the end of the fed-batch cultivation, the biomass and exopolysaccharide of N.flagelliforme increased distinctly to 1.16 g•L^-1 and 124 mg•L^-1, respectively.

Abstract: Nitrofurans residue in fishery products were dangerous for human health and still remain a big challenge in China. However, there are a few available methods to detect nitrofurans residue in fishery products. This study aimed at developing a high performance liquid chromatography (HPLC) method to detect four nitrofurans (furaltadone, nitrofurazone, nitrofurantoin and furazolidone) residue in fishery products sensitively . Firstly the nitrofurans were extracted from samples with ethyl acetate and then concentrated with rotary evaporator. After mobile phase dissolved and normal hexane defatted, the analytes were quantified with an external standard method by HPLC. The results showed that the linear range was 0.025~1.000μg/mL with correlation coefficients all more than 0.998 and the quantification limits of furaltadone, nitrofurazone, nitrofurantoin, furazolidone, were 11.0, 6.00, 13.0 and 7.00μg/kg respectively. The method was used to detect the nitrofurans in fishery products prepared with recovery rates from 72.2% to 107.4% and relative standard deviation (RSD) varied from 6.2% to 10.4%. Therefore, this method can be used for monitoring nitrofurans in commercial fishery products, improving the safety of commercial fishery products in China.

Abstract: The properties of corn flour prepared by fermenting, wet-milling and extruding were investigated. The results showed that RVA parameters of the corn flours by fermenting compared with wet-milling decreased but enthalpies slightly increased. Extruded samples had no peak (RVA) and no differential scanning calorimetry (DSC) endotherm. In fermenting and wet milling starches a bimodal distribution of chain lengths( fractionⅠand Ⅱ) were found by gel permeation chromatography but extruded starches only one fraction.

Abstract: Aspergillus niger can produce an acid-stable α-amylase as well as an acid-unstable one, the relation between the structural differences and their acid-resistant capability is of great interest. In this paper, the primary parameters, secondary and tertiary structures of these two types of α-amylases was analyzed and compared, the results shows that they has 67% sequence identity and high homology in secondary and tertiary structure. The acid-stable α-amylase has lower isoelectric point and higher molar percent of acidic amino acid than the acid-unstable one. The four major structural differences of these two types of enzymes is located at residues 132-138, 206-212, 329-335 and 378-382 and formed vary fold pattern.

Abstract: The nutrition composition of Longan seeds was analysed in this paper.The results showed that starch,reducing sugar and protein are abundant in Longan seeds,as well as mineral elements which mainly contain K,Ca,Mg,P.The content of VA(＜0.56µg/100g) and VE(0.55mg/kg) were determined.It suggests that Logan seeds are favorable nutrient resource of health food.

Abstract: A rapid multiplex-PCR method was established in order to detect three foodborne pathogenic bacteria including Salmonella typli，Vibrio parahaemolyticus and Listeria monocytogenes in aquatic products. Three pairs of oligonucleotide primers were designed for multiplex-PCR amplification according to gene coding invasion protein A of Salmonella typli，gene coding immune response of Vibrio parahaemolyticus and regulation histone gene of Listeria monocytogenes. The amplified fragment sizes of these three bacteria were 213 bp, 369 bp and 517bp, respectively．The specificity of the multiplex- PCR was high and the minimum detection limit reached 103 CFU/mL. The multiplex-PCR method was used to analyze three aquatic product samples compared with national standard methods, the coincidence rate of two methods reached 100%. The method developed in this study had high sensitivity and specificity, which could be applied for the rapid detection and molecular epidemiology survey of food-borne pathogenic bacteria in aquatic products．