复合酶法提取鸭血抗氧化肽工艺的研究

以SN-TCA指数和DPPH自由基清除率为指标,采用复合酶(木瓜蛋白酶:中性蛋白酶为2:1),确定制备鸭血抗氧化肽的最佳复合酶解工艺。并在单因素基础上,采用Design-Expert7.0软件设计回归正交实验,用响应面分析法优化各因素及其交互作用的最佳组合。结果表明:温度为55.21℃,时间为1.70h,底物浓度为10.0%,酶用量为0.45AU/g,在此条件下进行实验得出:SN-TCA指数为49.13%,DPPH.清除率为80.75%。     

κ-卡拉胶和魔芋胶及其复配对咸蛋清鱼糜混合凝胶品质的改良

研究了κ-卡拉胶和魔芋胶及其复配在添加了咸蛋清的罗非鱼鱼糜凝胶中的应用,通过质构测定和感官评价,结果发现:κ-卡拉胶和魔芋胶及其复配均能够显著提高鱼糜凝胶的凝胶强度和持水力(p<0.05),随着添加量的增大,鱼糜凝胶断面也逐渐变得粗糙从而影响其质构。当κ-卡拉胶与魔芋胶的质量比为2:1,添加量为0.1%时,咸蛋清鱼糜凝胶品质较好,整体接受性强。     

高温风干成熟工艺对风鸭风味物质的影响

为研究高温风干成熟工艺对风鸭风味物质的影响,采用固相微萃取结合气相色谱/质谱联用技术(SPME-GC/MS)检测了原料、腌制、风干24、48、72、96 h不同工艺阶段风鸭中挥发性风味化合物的种类及相对含量,并利用主成分分析方法分析影响风鸭风味的主要因子。共检测到110种挥发性风味成分,分别为醇类(38)、烃类(24)、醛类(19)、酮类(9)、胺类(7)、呋喃类(4)、酯类(3)、酸类(2)、含硫化合物(2)、醚类(1)和含氮化合物(1)。第一主成分主要由醛、醇类和甲基酮构成,第二主成分主要由烃、醇和醛等组成。风鸭风味的形成受脂肪氧化分解、蛋白质降解及微生物共同作用的影响,通过控制加工工艺参数可以调控高温成熟风鸭风味的形成。     

裸装卤制全鸭中菌相初步研究

采用选择性培养基分离裸装卤制全鸭中的菌相并对分离出的菌株进行生理生化试验检验,从裸装卤制全鸭中分离获得乳酸菌、微球菌和葡萄球菌属、肠杆菌科菌株各2株以及热杀索丝菌、假单胞菌菌株各1株;研究了其在储藏过程中细菌数量的变化情况,发现整个过程中乳酸菌、肠杆菌、热杀索丝菌、假单胞菌、微球菌和葡萄球菌生长趋势基本一致,均呈现出明显的增长趋势,从数量上来看,乳酸菌为裸装卤制全鸭中的主要优势菌.     

Rehydration kinetics at 5 and 15 °C of dry salted meat

The surface of meat products during intermittent drying is successively subjected to dehydration and rehydration processes. The aim of this paper was to study the rehydration kinetics at two temperatures (5 and 15 °C) of salted ground pork, (2% or 4% NaCl) dried to different water contents, (10%, 20% and 35%) using Peleg and Weibull’s models. Surface structure of dried samples was analyzed with electron microscopy and related to rehydration kinetics. The equilibrium water content decreased with temperature and increased with NaCl, but was not affected by the initial water content. The rehydration rate at the beginning decreased with water content and was significantly higher at 5 °C than at 15 °C, but it was not significantly affected by NaCl content. However, the equilibrium water decreased with temperature and tended to increase with NaCl content, but was not affected by the initial water content. High level of dehydration resulted in a more damaged and porous meat matrix. This microstructure may contribute to accelerating the rehydration process.     

风鸭的腌制发酵工艺研究

本试验研究了用复合发酵剂生产风鸭的工艺条件。通过正交试验确定了鸭胚腌制的最佳条件为食盐浓度8％,蔗糖3％,复合香辛料（花椒八角1：1混合）1．5％,腌制时间12h。通过单因素试验与正交试验确定了最佳的发酵条件：植物乳杆菌、戊糖乳杆菌、变异微球菌与汉逊德巴利氏酵母菌之间的菌种比例1：2：1：2,接种量1．5％,发酵温度22℃,发酵时间73h,所得风鸭pH值为5．18,氨基酸态氮含量为0．75％。     

Influence of Water Compositions and Conditioning on Flux Enhancement in an Immersed Membrane System

Abstract

The objective was to quantify the importance of operational conditions, aeration, and physico‐chemical conditioning on membrane fouling intensity. The suspension filterability was also analysed by using frontal filtration and a cake filtration model. Results pointed out the moderated role of aeration to reduce compound accumulation on the membrane surface. It did not appear as a determining criterion to prevent membrane fouling. In contrast, the physico‐chemical conditioning appeared as a determining criterion to increase critical flux. According to the experimental conditions 200 l/m²/h/bar membrane permeability could be maintained transmembrane pressure (TMP) when filtering stored rainwater. This permeability value was 2–3 times higher than the values obtained without conditioning. Moreover, according to the low turbidity of such stored rainwater and because of the high selectivity of the membrane, the coagulation step, a very low amount of 10 mg/l FeCl₃, was sufficient to intensify the filtration step. This conditioning interest appeared less significant when filtering salted water in immersed membrane systems, but a 20 mg/l FeCl₃ addition appeared sufficient to double the value of critical flux. Nevertheless filtration in frontal mode pointed out the significant impact of physico‐chemical conditioning in reducing the cake deposit hydraulic resistance.     

常温风味烤鸭的加工工艺研究

通过试验确定的烤鸭加工工艺参数分别为:淡盐卤浓度为8～9波美度;麦芽糖、清水、白酒比例是1∶7∶0.2;晾坯12h以上;烤制温度是180～200℃,烤制时间为45min;杀菌温度121℃,杀菌时间35min。该工艺生产出来的烤鸭产品五香烧烤味浓郁,常温下至少保存3个月,其理化指标也符合国家标准。     

泡椒鸭舌加工工艺

介绍了采用预调制的泡椒浸渍液泡制鸭舌的加工工艺。试验结果表明,鸭舌在90～95℃水中预煮lOmin,并于0～5℃浸渍液中腌制24h,无菌真空包装,IO＆C杀菌20min。所得产品品质最佳,常温下保质期可达6个月。     

Microplastics contamination in tidelands of the Osaka Bay area in western Japan

Recently, researchers have been examining the actual state of microplastics contamination in the environment. However, pollution in high biodiversity environments such as tidelands has not been sufficiently investigated. Therefore, to assess the actual level of microplastics pollution therein, we conducted a survey of the tidelands of Osaka Bay in Japan to develop a model that included basins in urban and suburban areas. We quantified the levels of microplastics in the mud from four of Osaka Bay's tidelands and detected them based on three inhabitants of the main river estuary tideland, namely, bivalves (Corbicula japonica), crabs (Chiromantes dehaani) and a tufted duck (Aythya fuligula). Microplastics ranging in size from 300 μm to 5 mm were targeted, and the results indicated that the concentration of microplastics in the mud tended to increase with tideland proximity to an urban area where the density of the human population was the highest. Microplastics were detected in 10% of the bivalves and 6.7% of the crabs (n = 30 in both cases), and eight pieces of microplastics were detected in the stomach of one tufted duck. These results indicate that the mud in tidelands near urban areas had more microplastics. In addition, the results suggest that microplastics contamination levels may be higher in higher order predators in the food web.