Sensory description of gluten-free bread using rapid sensory methodologies

This paper describes the sensory profile of gluten-free bread prepared with teff, sorghum and yacon flours, using Check-All-That-Apply (CATA) and Just-About-Right (JAR) methods. The sorghum flour bread was characterised by porosity, reddish colour, bread and yeast aroma, crust hardness, floury and sour aroma, and unpleasant consistency. The teff flour bread was characterised by floury flavour, salty taste, grittiness and cereal aroma. The flavour attributes of both products were judged as ideal. The yacon flour bread was characterised as sweet aroma, softness, rubbery, unpleasant taste, chewiness, moistness, adhesiveness and bitterness. The attribute sweet taste was considered beyond the ideal and salty taste below the ideal. The flour-mixed formulation was characterised by a pleasant aroma, chewiness and springiness. The attributes salty taste, sweet taste and softness were considered ideal. The mixture of these flours contributes to obtaining gluten-free bread with better sensory characteristics than when using these flours alone.     

中温发酵酸乳的挥发性风味成分与感官特性的研究

通过正交实验研究了球杆菌比例、全脂乳浓度、发酵终点以及蔗糖添加量对中温发酵酸乳的感官和挥发性风味成分的影响。以九个不同工艺配方为研究对象,采用描述分析感官评价法和固相微萃取结合动态顶空方法对酸乳的感官评价值和风味成分进行测定,并运用主成分分析法和偏最小二乘分析法得到感官结果和仪器测定结果的相关性。结果表明:球杆菌比例和全脂乳浓度是影响酸乳风味和挥发性风味成分的重要因素。偏最小二乘回归分析得到3种气味、3种滋味和2种余味与挥发性成分、乳酸和柠檬酸量的相关性。      

Physicochemical characterization and sensory evaluation of yogurts incorporated with beta-carotene-loaded solid lipid microparticles stabilized with hydrolyzed soy protein isolate

Food Science and Biotechnology - Beta-carotene is an extremely interesting bioactive compound in the food industry due to its antioxidant capacity and pro-vitamin A activity. However, its...     

膳食纤维强化酸奶的流变学特性及其感官品质研究

对膳食纤维(Dietary Fiber,DF)强化酸奶的流变学特性及感官品质进行了研究.结果表明,膳食纤维不同强化量酸奶为假塑性流体,流变学特性符合冥律模型,表观黏度随膳食纤维加入量的增加而增加.触变性检验表明,膳食纤维添加量越大,触变性越小.随着贮藏时间的增加,酸奶黏度逐渐减小,而且膳食纤维添加量越多,减小的趋势越小.从健康和嗜好多方面考虑,酸奶中添加质量分数为1.0%的膳食纤维较为恰当.     

淀粉及变性淀粉在酸乳中的应用研究进展

主要介绍国内外各种淀粉和变性淀粉在酸乳中的应用研究进展,以及未来的发展趋势和在酸乳生产中存在的问题。      

糖尿病人食用酸牛奶的开发研究

通过分析糖尿病人饮食要求特点和适用于酸奶的配方特点,探讨了甜味剂、菌种的添加量以及保温发酵时间对酸奶口感等感官质量的影响,得到了糖尿病人可以食用的无糖低热量酸牛奶生产工艺条件和产品配方。      

Critical review of techniques and methodologies for characterization of emulsion stability

The efficient development and production of high quality emulsion-based products depends on knowledge of their physicochemical properties and stability. A wide variety of different analytical techniques and methodologies have been developed to characterize the properties of food emulsions. The purpose of this review article is to provide a critical overview of the most important properties of emulsions that are of interest to the food industry, the type of analytical techniques that are available to measure these properties, and the experimental protocols that have been developed to characterize the stability of food emulsions. Recommendations are made about the most suitable analytical techniques and experimental protocols needed to characterize the stability and properties of food emulsions.     

Probiotic viability and physico-chemical and sensory properties of plain and stirred fruit yogurts made from goat's milk

Probiotic plain and stirred fruit yogurts were made from goat's milk using bacterial cultures comprising, Lactobacillus acidophilus LA-5, Bifidobacterium animalis subsp. lactis BB-12 and Propionibacterium jensenii 702. The products were stored at 4°C for 4weeks, during which time the viability of the yogurt starter culture and probiotic bacteria was analysed weekly. P. jensenii 702 demonstrated the highest viability (10(8)cfu/g) in all types of yogurt throughout the storage period, while the viability of the bifidobacteria (～10(7)cfu/g) also remained above the minimum therapeutic level. The viability of L. acidophilus LA-5 fell below 10(6)cfu/g in yogurts, however, the addition of fruit juice appeared to support the viability of lactobacilli, with higher microorganism numbers observed in fruit yogurts than in plain yogurt throughout the shelf life. Addition of fruit juice significantly increased the syneresis, and decreased viscosity and water holding capacity of yogurts (p<0.05), and also enhanced their sensory acceptability.     

Influence of three non-sensory factors on consumer choice of functional yogurts over regular ones

To better understanding the consumer choice of functional foods, a choice-based conjoint study was carried out to investigate the influence of three non-sensory factors on consumer choice of functional yogurts over regular ones. Four attributes were considered in the conjoint study: type of yogurt (regular, enriched with antioxidants and enriched with fibre), brand (national familiar, national unfamiliar, and foreign familiar), price (low, regular and high) and claim (with and without ‘reduced disease risk’ health claim). Eighteen choice sets, each composed of three stimuli (regular yogurt, enriched with antioxidants and enriched with fibre and varying the brand, price and claim levels) were evaluated by 103 consumers. For each choice set, consumers had to indicate which yogurt would normally buy. A questionnaire on consumer attitude towards health and nutrition was answered by participants after the choice task. Brand, price and health claims highly significantly affected consumer choice of functional yogurts. The relative importance of brand was similar to that of type of yogurt. Therefore, results suggested that non-sensory factors such as brand and price could have an important impact on consumer perception of functional foods. The impact of brand, price and health claims was affected by consumer interest in health issues.     

Characterization of functional, biochemical and textural properties of synbiotic low-fat yogurts during refrigerated storage

This study examined the influence of exopolysaccharides (EPS) produced in situ on the viability of Streptococcus thermophilus, Lactobacillus delbrueckii ssp. bulgaricus and probiotics, the proteolytic and ACE-inhibitory activities, and textural and rheological properties of inulin-containing probiotic yogurt during refrigerated storage. Two types of yogurt were prepared using strains of S. thermophilus not producing EPS (NEPY) and producing EPS (EPY). The yield of crude EPS increased (by 2.4 times) until day 21 of storage. Presence of EPS showed a protective effect on the survival of L. delbrueckii ssp. bulgaricus and Lactobacillus acidophilus but not on S. thermophilus, Lactobacillus casei and Bifidobacterium longum. No changes in post-acidification, lactic acid content or the ACE-inhibition activity of the two types of yogurt were observed. Overall, EPS containing yogurts exhibited higher proteolysis in the presence of inulin and probiotics (0.698 units) than the corresponding control (0.563 units). The storage and loss moduli (Pa), yield stress (Pa), consistency index (Pa s) and thixotrophic behaviour (Pa s⁻¹) of both samples were similar at day 1 and the influence of EPS was observable only after day 7. Such a variation of the effect of EPS on the textural and rheological properties of low-fat yogurt appears to be partially due to the presence of probiotics.     

快速感官分析技术在葡萄酒香气感官分析中的应用

采用快速感官分析技术——Napping~?结合Ultra Flash Profiling(UFP)对来自中国4个产区的12款赤霞珠干红葡萄酒进行香气感官评价,采用普氏多维向量分析(procrusts multiple factor,PMFA)、Indscal模型和聚类分析3种多元统计分析对感官数据进行分析。结果表明,不同产区的葡萄酒具有明显的产区特征性并且具有相似的香气特征,其中3种多元统计分析共同认为,晋西产区和烟台产区的赤霞珠葡萄酒具有明显的产区特征性,晋西产区的葡萄酒都具有黑醋栗、红色水果和山楂的香气,烟台产区的葡萄酒则具有显著的烟熏香气特征。来自宁夏产区和新疆产区的葡萄酒之间的差异性在不同分析方法间略有差别,PMFA和聚类分析显示,二者的差异性较小,而Indscal模型则可以较好区分。此外,宁夏产区的葡萄酒具有青椒和甜香料的香气,而来自新疆产区的葡萄酒则具有更显著的烘烤、李子干和花香的香气。研究结果表明,快速感官分析技术可以准确地对葡萄酒进行感官评价。     

Comparison between rabbit lines for sensory meat quality

Rabbits from three synthetic lines were used in the experiment. Line R was selected for growth for 24 generations. Lines V and A were selected for litter size at weaning for 30 and 33 generations, respectively. Sensory analysis was carried out on the Longissimus muscle. The parameters evaluated were: juiciness (J), hardness (H), fibrousness (F), flouriness (Fl), intensity of rabbit flavour (IRF), aniseed odour (AO), aniseed flavour (AF), liver odour (LO) and liver flavour (LF). A Bayesian analysis was performed. Line V was only 82% as juicy as line R. Line V was 18% harder and 17% more fibrous than line R. Lines A and R had the same H and F. No differences in Fl were found. Small effects were found for flavour traits. We conclude that line origin has an influence on some sensory traits determining rabbit meat tenderness.     

Viability of probiotic micro-organisms during storage, postacidification and sensory analysis of fat-free yogurts with added whey protein concentrate

The aim of this research was to evaluate the effect of the addition of whey protein concentrate (WPC) on the viability of Lactobacillus acidophilus and Bifidobacterium longum and on postacidification throughout the shelf life of fat-free yogurts, and also to analyse the sensory characteristics of the products. Postacidification was not significantly changed by the addition of WPC, but was decreased by Lactobacillus bulgaricus inoculation. WPC did not influence the viability of the lactic acid bacteria ( L. bulgaricus and Streptococcus thermophilus ), but it improved the growth and survival of the micro-organisms L. acidophilus and B. longum , especially the former. The panellists did not identify significant differences ( P <  0.05) of the yogurts due to the addition of WPC.     

Comparison of HPLC and GLC methodologies for determination of glucosinolates using reference material

 The reference material rapeseed of known glucosinolate composition, was analysed by HPLC and GLC and two commercially available glucosinolates (glucotropaeolin and sinigrin) were used as internal standards. The HPLC method enabled determination of 11 different glucosinolates (as desulphoglucosinolates) that occur in the rapeseed. Only seven glucosinolates (as trimethylsilylated desulphoglucosinolates) were separated by GLC. The latter method did not allow the determination of methylsulphinylalkyl glucosinolates (glucoiberin, glucoraphanin and glucoallysin) and did not separate optical isomers of 2-hydroxy-3-butenyl glucosinolate (progoitrin and epi-progoitrin). Statistical evaluation of data (t-test, F-test) revealed no significant differences between the tested methods at the 95% confidence level. The advantages and disadvantages of both widely used chromatographic methods are discussed. Received: 26 May 1997 / Revised version: 11 July 1997     

Comparison of HPLC and GLC methodologies for determination of glucosinolates using reference material

 The reference material rapeseed of known glucosinolate composition, was analysed by HPLC and GLC and two commercially available glucosinolates (glucotropaeolin and sinigrin) were used as internal standards. The HPLC method enabled determination of 11 different glucosinolates (as desulphoglucosinolates) that occur in the rapeseed. Only seven glucosinolates (as trimethylsilylated desulphoglucosinolates) were separated by GLC. The latter method did not allow the determination of methylsulphinylalkyl glucosinolates (glucoiberin, glucoraphanin and glucoallysin) and did not separate optical isomers of 2-hydroxy-3-butenyl glucosinolate (progoitrin and epi-progoitrin). Statistical evaluation of data (t-test, F-test) revealed no significant differences between the tested methods at the 95% confidence level. The advantages and disadvantages of both widely used chromatographic methods are discussed. Received: 26 May 1997 / Revised version: 11 July 1997