自制热泵烘房干燥绿头板鸭产品与传统工艺产品的初步比较研究

采用不同温度对皖山绿头野鸭进行烘干发酵,达到40%的固定含水率。对自制板鸭样品与鲜鸭、传统工艺皖山板鸭和市售不同类型的板鸭进行感官评价及理化分析。结果表明:烘干温度应选取40~50℃之间,烘干时间控制在16~25 h,产品水分含量控制在40%左右,感官评价较好,产品氨基酸含量随烘干时间的延长而升高,给板鸭的特殊风味做出了贡献,同时这个温度范围下过氧化值相对较低,既能保证板鸭的口感和鲜味,同时能够降低成本,保证产品的品质,适合皖山板鸭工业化生产。      

羊肉松加工工艺的改进

在羊肉松传统加工工艺上提出了新的加工改进方案,适合于不同品质肉的加工,适合于机械化连续生产,提高生产效率。     

Chemical and microbial stability of high moisture dried apricots during storage

BACKGROUND: This study was conducted to determine the chemical and microbial stability of high moisture (HM) dried apricots during storage at 5, 20 and 30 °C for a period of 8 months. HM dried apricots were obtained by rehydrating dried apricots in ‘water’ and ‘water + H₂O₂’. RESULTS: Analysis of kinetic data suggested first‐order models for loss of SO₂ and non‐enzymatic browning reactions. Higher storage temperatures increased the rate of SO₂ loss and formation of brown colour in HM dried apricots. Results from extensive colour measurements (non‐enzymatic browning, reflectance colour and β‐carotene) revealed that the colour of HM dried apricots stored at 5 °C was almost unchanged during 8 months of storage. The colour of samples stored at 30 °C was unacceptable starting from 2 months of storage. Total mesophilic aerobic bacteria counts decreased 0.7, 1.1 and 1.5 log cycles after 8 months of storage at 5, 20 and 30 °C, respectively. For the same storage period, the decrease in mesophilic bacteria was 0.62 log cycle in samples rehydrated in ‘water + H₂O₂’ and stored at 20 °C. CONCLUSION: These results suggest that HM dried apricots should be stored at temperatures lower than 20 °C to preserve the characteristic golden yellow colour. A relatively low level of SO₂ (1458 mg kg^?1 at 200 g kg^?1 moisture level) was sufficient to prevent the growth of spoilage organisms in HM dried apricots at all three storage temperatures. Copyright © 2008 Society of Chemical Industry     

羊肉的漂洗脱膻及风味羊肉丝的研制

采用漂洗法对羊肉进行脱膻处理,研究了温度、pH、肉水比及漂洗次数对脱膻效果的影响,利用单因素实验对漂洗条件进行了选择.同时研制了风味羊肉丝的加工工艺,利用正交实验对产品主要配料及主要工艺条件进行了优选.结果表明:利用温度40℃、pH8.2、肉∶水=1∶7的漂洗液对羊肉进行5次漂洗处理,脱膻效果良好;羊肉丝产品配方中添加酱油6%、食盐4%、白砂糖2.5%,在55℃下烘干2h,后于200℃烘烤2min,所得的羊肉丝风味品质良好.     

市售咸干鲅鱼的安全性分析

为了初步探究咸干鲅鱼的安全问题,该研究以青岛市售的8种咸干鲅鱼为研究对象,对其理化和安全指标进行检测,包括样品的水分含量、盐含量、亚硝酸盐含量、挥发性盐基氮(TVB-N)、生物胺含量、硫代巴比妥酸值(TBA)以及过氧化值(POV)含量。结果表明,市售的8种不同水分、盐分的咸干鱼安全评价指标各不相同,其中粗盐腌制的咸干鱼亚硝酸盐含量和TBA含量较高;低盐高水分的咸干鱼亚硝酸盐含量和生物胺总量较高,TVB-N含量也相对较高,但是感官评价值最高;高盐咸干鱼亚硝酸盐含量低,感官评价低,8种样品这些指标的含量都在安全范围内,但脂肪氧化指标POV均超过限量标准。     

Fatty acids and cholesterol oxidation in salted and dried shrimp

The aim of this work was to evaluate the occurrence of cholesterol oxidation products and to analyze the lipidic profile in salted–dried shrimp. Fifty samples of salted–dried shrimp were evaluated, and the cholesterol oxides (7β-OH, 7α-OH, 7-Keto and 25-OH) were quantified by high-performance liquid chromatography. The cholesterol oxides: 7β-OH (34.63–72.56 μg/g), 7α-OH (5.02–12.12μg/g), 7-Keto (7.44–32.68 μg/g) and 25-OH (2.37–22.88 μg/g) were determined in all samples analyzed. Regarding to the total cholesterol content and the average thiobarbituric acid reactive substances (TBARS) content, the results ranged from 73.88 to 247.69 mg/100 g, and 0.02 to 1.30 mgMA/kg, respectively. The fatty acids profile was: 27.48% saturated, 43.90% monounsaturated and 28.61% polyunsaturated. The presence of cholesterol oxidation products and the values of TBARS indicate the degree of oxidation of this product, which was probably initiated by inadequate conditions of processing and storage.     

Effects of sea trout egg quality on stability of salted roe during cold storage

Sea trout eggs were salted in NaCl solution after 4 and 14 days of cold storage. The study indicated that the egg resistance to crushing decreased during cold storage from the initial 220 g to 180 g after 14 days. Changes in hardness of the egg membrane accelerated salt diffusion by about 30% to 80% during immersion in NaCl solution. Salting the eggs to 2.3% and 4.0% NaCl content decreased the hardness during cold storage, the decrease being larger in the roe manufactured from a lower quality raw material. In the eggs containing 5.3% and 7.0% NaCl the resistance to crushing increased during storage at 4°C to the extent similar in both egg freshness states obtained prior to salting. The salt content in sea trout eggs ranging from 23% to 7.0% only slightly activated hydrolysis and oxidation of lipid components at 4°C. Lipid oxidation was more rapid in eggs salted after 14 than in those salted after 4 days of storage in ice. Carotenoids of the salted eggs showed a decrease in undesirable cis-bonds during cold storage. Salting the sea trout eggs after 14 days of storage at 2°C shortened the storage time of the final product at 4°C by at least 1 month as compared to the salted roe kept in ice for 4 days before salting.     

鱼油纳米乳的制备及贮藏稳定性研究

采用高压均质法,以乳清分离蛋白(WPI)乳化包埋鱼油制备鱼油纳米乳。采用单因素实验研究了主要因素对包封率和吸光比(SRI)的影响,并以包封率为指标,进行正交实验优化工艺配方。同时以不同压力处理的鱼油纳米乳为对照,分别考察了4、25℃条件下鱼油纳米乳的贮藏稳定性。结果表明:最佳工艺配方为乳清分离蛋白质量浓度25 g/L,鱼油添加量100 g/L,均质压力80 MPa,均质次数4次。采用最佳工艺配方制备的鱼油纳米乳的包封率为96.4%,SRI为0.113。稳定性实验结果表明鱼油经纳米乳包埋可显著提高鱼油氧化稳定性,高压处理有利于提高鱼油纳米乳的稳定性,鱼油纳米乳在4℃的贮藏稳定性高于25℃的贮藏稳定性,80 MPa处理鱼油纳米乳经4、25℃放置30 d乳析指数分别为0、1.4%,鱼油纳米乳经25℃放置60 d后过氧化值及渗漏率分别为4.25 meq/kg、5.89%。     

Monitoring volatile and nonvolatile amines in dried and salted roes of tuna (Thunnus thynnus L.) during manufacture and storage

Dried and salted roe, obtained from the reproductive organs of female tuna (Thunnus tynnus L.), is a typical fish-based food in the Mediterranean area of Spain. In the present study, we monitored the formation of volatile amines (trimethyamine nitrogen [TMA-N] and total basic volatile nitrogen [TBVN]) and nonvolatile amines (biogenic amines) in dried and salted tuna roe after processing and storage for 8 weeks at 4, 20, and 30 degrees C. The salting and drying process significantly increased the TBVN, cadaverine, tyramine, phenylethylamine, and tryptamine contents, and bacteria with histamine decarboxylase activity were detected both in raw and in dried and salted tuna roes. During storage of tuna roe, TMA-N and TBVN levels increased significantly after the fourth week of storage at 30 degrees C, whereas biogenic amine contents remained more or less constant. However, samples stored at 30 degrees C showed histamine formation after the first week of storage, with a concentration of < 50 ppm. The volatile and nonvolatile amine concentrations in tuna roe were below the consumer safety limit, with the exception of the total biogenic amine level in roe stored at 30 degrees C, which exceeded the European Community's recommended limit (300 ppm). These results indicate that in properly stored tuna roe, histamine formation will not represent a serious health risk to consumers unless the tuna roe has previously been mishandled.     

羊肉发酵香肠的研制

为了获得质量、口感较好的羊肉发酵香肠,通过发酵剂适应性试验,选择用植物乳杆菌、啤酒片球菌和木糖葡萄球菌按一定比例混合生产羊肉发酵香肠,完全符合发酵肉制品对发酵剂的要求,并可使3种菌的优势得到互补,使发酵速度加快,提高营养价值。试验表明采用这3种菌生产发酵香肠是切实可行的。     

Changes in salted yoghurt during storage

The study was conducted to determine the gross chemical composition and concentrations of free fatty acids (FFAs) and volatile compounds of salted yoghurt made from indigenous goat's milk. The effects of some chemical properties on sensory attributes of salted yoghurt were also studied. Changes in FFAs (P < 0.01) and volatile compounds were statistically significant (P < 0.05) during storage. The most abundant FFAs were 9‐octadecenoic (C_18:1), hexadecanoic (C₁₆), tetradecanoic (C₁₄) and decanoic (C₁₀) acids, respectively. Ethanol and ethyl acetate were principal volatile compounds through the end of storage period. The storage period affected the intensity of flavour attributes and overall flavour score of salted yoghurt (P < 0.05). According to factor analysis result, chemical compounds including volatiles, FFAs up to C₁₄, tyrosine and titratable acidity, and flavour attributes explained 86.50% and 55.33% of total variance, respectively.     

Quality of dried white salted noodles affected by microbial transglutaminase

To examine the potential application of microbial transglutaminase (MTGase) in oriental noodle making, the effects of various MTGase addition levels on the rheological, textural and structural properties of noodles were investigated using good quality (‘Red Bicycle’) and poor quality (‘Sandow’) wheat flours. Addition of MTGase at 5–20 g kg^?1 levels, but not at 1 g kg^?1 level, to the two different wheat flours decreased rapid visco‐analyser (RVA) parameters of hot paste viscosity and final viscosity while increasing breakdown. For fresh white salted noodle dough sheets, the storage modulus (G′) and loss modulus (G″) increased significantly at 1 g kg^?1 MTGase addition for both types of flour, but there was no clear trend with higher levels of MTGase. For dried white salted noodles, textural parameters (tensile force, hardness and gumminess) generally increased, cooking loss was little affected and the yield of the cooked noodle was significantly decreased by MTGase. Color was slightly adversely affected. Scanning electron microscopy (SEM) results indicated that physical properties of dry noodles were improved through the formation of cross‐links [ε‐(γ‐glutamyl)lysine] by MTGase. Copyright © 2005 Society of Chemical Industry     

淡水鱼油微胶囊的制备及其储藏稳定性

以草鱼内脏提取鱼油作为微胶囊芯材,辛烯基琥珀酸淀粉酯分别与阿拉伯胶、玉米糖浆复配作为壁材,采用喷雾干燥法制备淡水鱼油微胶囊。测定2种复合壁材制备的鱼油微胶囊的性质和微观结构,并根据氧化反应动力学预测鱼油及鱼油微胶囊的货架期,气相色谱法分析微胶囊化前后鱼油和60℃储藏10d后鱼油及鱼油微胶囊脂肪酸含量的变化。结果表明:以辛烯基琥珀酸淀粉酯和玉米糖浆为壁材制备得到的鱼油微胶囊包埋率高,货架期长,储藏稳定性好,可对淡水鱼油本身的功能性成分起到良好的保护作用。     

Physicochemical properties and storage stability of spray‐dried soya bean sprout extract

Amylase is a very important enzyme due to its wide food applications. To preserve amylase activity in soya bean sprout extract (SSE), SSEs were spray‐dried with 10% maltodextrin and 0–3% alginic acids, and their physicochemical properties and storage stability were compared with freeze‐dried one. SSE exhibited maximum amylase activity at pH 7.0 and 60 °C, with the most active substrate specificity towards soluble starch. Spray‐dried SSEs exhibited higher water solubility index (WSI) and in vitro relative amylase activity but lower water vapour sorption (WVS) and smaller particle size than freeze‐dried SSE. For spray‐dried SSEs, particle size, WSI and in vitro relative amylase activity increased while WVS decreased with increasing % alginic acid. This study demonstrated that spray drying of SSE, especially with 10% maltodextrin and 2% alginic acid, was effective in keeping amylase active and stable during 7‐week storage at room temperature (25 °C).     

羊肉泡馍汤料的配置及保质期的研究

选用新鲜羊肉,经预煮、卤煮、高温杀菌等工艺,选用具有保健功能的八珍香料及调味料等辅料,调制出具有独特风味的羊肉泡馍汤料,并进行了保质期试验。     

盐生野菜(黄须菜)干制工艺研究

黄须菜用500mg/kgZnCl2溶液(pH8～9)热烫90s,然后80℃入箱干燥15min后调至60℃,恒温干燥10～12h后回潮包装,即可得到色泽浓绿的合格产品。     

过热蒸汽对燕麦挂面贮藏稳定性及风味的影响

本文采用过热蒸汽钝化燕麦中脂质降解酶,并通过测定脂肪酸组成、脂肪酸值、生育酚和挥发性风味成分的变化来分析其对燕麦挂面贮藏稳定性的影响。结果表明,过热蒸汽处理后燕麦挂面中脂肪酶和过氧化物酶活性显著（p < 0.05）降低,脂肪氧合酶活性在贮藏后期显著下降。处理后的挂面脂肪酸值显著（p < 0.05）低于对照组,且贮藏12周后,190 ℃处理组中不饱和脂肪酸降解程度最低。同时,190 ℃处理组挂面贮藏期间生育酚的稳定性显著（p < 0.05）提升。GC-MS结果表明,己酸、2-戊基呋喃是燕麦挂面贮藏期间所产生的主要挥发性风味物质,而170、190 ℃处理可明显抑制其产生。综上,190 ℃过热蒸汽处理对提高燕麦挂面贮藏稳定性、改善风味有积极作用。     

Improved utilization of flesh from mackerel as salted dried fish cakes

The composition and yield of mince prepared by passing mackerel ( S. scombrus ) frames through a flesh-bone separator were determined. Salt (10 to 40%) was added to the unwashed mince to prepare dried cakes with enhanced keeping quality. The dried cakes were assessed for peroxide and TBA values, total viable count and for sensory attributes after preparation and after a 3-month storage period at 29±1°C. The cakes were reconstituted by desalting in boiling water. Salted dried cakes prepared with 15,20,30 and 40% salt were found to be stable and have little sensory deterioration over the 3-month storage period which is adequate to simulate distribution of products at tropical ambient temperature.     

Preparation and storage stability of juices from different carrot species

Carrot juice was prepared from each of yellow-, orange-, and purple-coloured carrots. Juice preparation included sorting, washing, peeling, acid-blanching, chopping, juicing, sterilization, and bottling steps. Bottled juices were stored in incubators which were kept at 5 °C, 20 °C, and 27 °C. Analytical determinations of pH, total soluble solids, maximum absorbance, reducing sugar, ascorbic acid, and β-carotene were made in suitable time intervals. Each of the three types of carrot juice kept at 27 °C deteriorated organoleptically in the first two weeks of storage. Juices stored at 20 °C and 5 °C were stable up to seven and twelve weeks, respectively. It was concluded that each of the carrot species can well be used for the preparation of carrot juice.     

小麦粉加工精度对挂面储藏期间脂质稳定性的影响

研究不同加工精度小麦粉对挂面储藏期间脂质稳定性影响。结果表明,挂面储藏过程中,总脂和结合脂含量总体呈现下降趋势,游离脂含量先下降后升高再下降,脂肪不断消耗;游离脂肪酸值显著升高(P<0.05),低加工精度小麦粉制得的挂面脂质水解程度较高且水解速率快,12周后脂肪酸值略有降低;低加工精度的挂面脂肪酶活显著下降(P<0.05);低加工精度挂面亚油酸含量在0～12周显著上升(P<0.05),随后显著降低(P<0.05);GC-MS测定结果表明挂面中挥发性物质乙酸、己酸和壬酸含量明显升高,加工精度越低的小麦粉制得的挂面中酸性物质含量增幅越大,氧化酸败速度越快。因此,低加工精度小麦粉制得的挂面在储藏过程中脂质水解和氧化程度较高,脂质稳定性较低。