不同品牌郫县豆瓣酱挥发性成分的比较研究

采用同时蒸馏萃取,结合气-质联机对2种不同品牌郫县豆瓣酱的挥发性成分进行了比较研究.研究结果表明：不同品牌的郫县豆瓣酱挥发性成分的差别比较大,如川花牌豆瓣酱鉴定出86种,丹丹牌78种;2种品牌豆瓣酱挥发性成分都是酯类最多,其次是醇类,然后是醛酮类等,其中含量较大的成分有3-甲基丁醇、糠醇、芳樟醇、苯乙醇、3-甲基丁醛、糠醛、苯乙醛、3-羟基-2-丁酮、乙酸乙酯、十六碳酸乙酯、亚油酸乙酯、十八碳酸乙酯、4-乙基苯酚、4-乙基-2-甲氧基苯酚和2-甲氧基-4-乙烯基苯酚等.     

川味冷菜复合调味汁及其香辛料抑菌作用的研究

通过对红油味、姜汁味、蒜泥味３种川味冷菜复合调味汁抑菌作用的研究,发现各调味汁中所用的香辛料不同,对原料自身所携带的微生物及试验中选用的２种肠道病原菌的抑制程度各异。其中蒜泥味的抑菌作用最强,姜汁味次之,红油味几乎无抑菌能力。并揭示了配制冷莱复合调味汁时的用油量与调味汁的抑菌程度呈反比关系,为烹饪工艺科学化提供了一定的理论指导。     

高效液相色谱法检测酱油中羟脯氨酸的含量

实验建立了柱前衍生高效液相色谱分析酱油中羟脯氨酸(hydroxyproline,Hyp)含量的方法。样品经乙醇提取,以2,4-二硝基氟苯为衍生试剂,采用GeminiC18(4.6×250mm,5μm)色谱柱分离,检测波长为360nm。Hyp质量浓度与其峰面积在10～320mg/L范围内具有良好的线性关系,相关系数为0.9992。回收率为97.19%～110.18%,检出限为2.5mg/L。对实际样品中相对Hyp含量(表示为每克氨态氮中所含羟脯氨酸的毫克数)进行检测发现,纯酿造酱油在0.67～1.93mg/g之间,酸水解植物蛋白液在9.51～20.11mg/g之间,酸水解猪皮和猪肌肉分别为855.55,37.03mg/g,三类样品间存在较明显的差异。上述结果提示,Hyp并非胶原蛋白中所特有,但通过检测酱油样品中Hyp含量有可能区分酱油中是否添加酸水解蛋白液。     

用提取L-胱氨酸后母液勾兑酱油的利与弊

就提取Ｌ－胱氨酸后母液勾兑酱油时的利与弊问题以及如何消除其母液中的污染物进行了探讨。     

Stabilization of meat suspensions by organogelation: A rheological approach

The stabilization of suspensions is a relevant issue in several industrial applications and particularly in the food area. Water‐based systems are widely studied and they are commonly stabilized by the addition of hydrocolloids (such as polysaccharides or proteins) whereas for oil‐based products less information is available. In this paper, oil‐based meat suspensions are investigated, and the addition of organogelators is proposed as a potential solution to the stability problems currently observed in some practical applications. Investigated suspensions are obtained by grinding a meat phase with vegetable oil blends, thus yielding products typically used in the traditional southern Italian diet as spreadable spicy sauces or as oil‐based dressings for pizzas. The effects of proposed additives were investigated by destabilizing the modified suspensions (by centrifugation) and comparing their rheological characteristics and oil loss to those of the unmodified systems (i.e., without addition of stabilizers). It was observed that both additives exert a stabilizing action, even if one of them (monoglycerides of fatty acids) is more effective than the other, even at a very low concentration. The adopted rheological approach has proved very useful to determine the type and amount of the proper organogelator to be used as an oil suspension stabilizer.     

Sauces and dressings: a review of properties and applications

This comprehensive review of sauces and salad dressings covers the literature over the last decade with respect to physical and chemical properties and the applications of these products. As such, texturizing and structural systems (especially hydrocolloids) are described in detail and the application of polysaccharide thickeners as texture providers is described. Microbiological aspects of sauces are covered with relevant sections discussing the factors affecting microbiological activity and microbial spoilage and/or enhancement of a range of sauces. In addition, the use of carbohydrates and proteins as emulsifiers in many sauces is described. Quality aspects are given prominence in this review with sections being devoted to rheological and textural properties, chromatographic approaches and sensory aspects. Healthy sauces such as those having low sodium, reduced fat and cholesterol or containing inulin or microcrystalline cellulose are reviewed. Finally, for various sections the trends of the main findings as well as suggestions for future research are presented.     

A peculiar stimulatory effect of acetic and lactic acid on growth and fermentative metabolism of Zygosaccharomyces bailii

Stimulatory or protective effects of organic acids at low concentrations, e.g. acetic and lactic acid, on microorganisms have previously been reported. Especially in case of Zygosaccharomyces bailii, a peculiar growth stimulation by these two acids has recently been noticed. In order to elucidate this interesting phenomenon, growth and fermentative metabolism of Z. bailii was investigated in media with low pH (pH 4.0), high sugar (15% (w/v)) and different acetic and lactic acid concentrations. At both experimental temperatures (7 and 30 °C), a growth stimulation in the presence of 2.5% (v/v) lactic acid was observed. Furthermore at 7 °C, the yeast exhibited another unusual behaviour as it grew much faster in media containing 1.25% (v/v) acetic acid than in the control (without any acid). Production of fermentative metabolites was also increased together with the enhanced growth at both temperatures. These possible stimulatory effects of acetic and lactic acid should be taken into consideration when the acids are used at low doses for food preservative purpose. Presence of the acids may stimulate Z. bailii growth and fermentative metabolism, particularly at refrigeration temperature, consequently resulting in an earlier spoilage.     

Clustering of instrumental methods to characterize the texture and the rheology of slimy okra (Abelmoschus esculentus) suspensions

Okra (Abelmoschus esculentus) is one of the ingredients widely used in African gastronomy because of the unique slimy texture it gives to sauces. However, processing and formulation can affect the textural and rheological properties of these sauces, leading to unacceptable quality for the African consumer. The aim of this study was to select the instrumental measurements best enabling (a) characterization of the rheology and texture of slimy sauces prepared from okra and (b) monitoring its evolution during the preservation process. Thirty-seven slimy suspensions (sauces and purées) were measured with 16 rheological and textural parameters. A principal component analysis revealed that flow consistency index K and flow behavior index n were well correlated with visco-elastic, adhesive, and shear thinning properties, and that stringiness was well correlated with elongational, cohesive, and ductile properties. These two sets of measurement methods are sufficient to characterize their rheological and textural properties, and necessary to discriminate them according to their process and formulation.     

Relationships between antioxidant activity and quality indices of soy sauce: an application of multivariate analysis

Antioxidant activities (AA) and quality indices including the contents of total nitrogen, amino nitrogen, total acidity, sodium chloride, total solids (TS), non-salt soluble solids and Browning Index (BI) were determined in forty-one commercial soy sauces. The relationships between quality indices and AA were elucidated by multivariate analysis techniques. Results showed that production location, fermentation process and styles had significant ( P <  0.05) impacts on the characteristics of soy sauces. Satisfactory discrimination between dark and light soy sauces was achieved by principal component analysis. Using cluster analysis, the group of dark soy sauce with strong AA was obtained. Results from partial least squares regression (PLS) showed that TS and BI were two major indices contributing to the AA of soy sauce. Moreover, a PLS model was constructed to effectively predict AA of soy sauces based upon quality indices.