毛酸浆对酸羊奶感官品质的影响

以毛酸浆水提取物和羊奶为原料,采用Box-Benhnken响应面法对酸羊奶的最佳发酵工艺参数进行了优化,利用电子鼻分析了毛酸浆的添加对产品感官品质的影响。结果提示,毛酸浆对产品的感官品质影响显著,与羊奶可以产生协同增香的效果,与原味酸羊奶相比具有一定的抗氧化性。通过响应面优化所得的毛酸浆酸羊乳最佳发酵工艺参数为:毛酸浆提取物添加量7.5%,发酵剂添加量6.5%,43℃下发酵7 h。经此工艺制备的酸羊乳,提高了产品的营养价值,是一种颇具前途的功能性酸羊奶。      

Probiotic buttermilk-like fermented milk product development in a semiindustrial scale: Physicochemical, microbiological and sensory acceptability

Probiotic buttermilk-like fermented milk in different flavors in versions with sucrose and sucralose were processed in a pilot plant. The Mesophilic Aromatic Culture CHN-22 and Bifidobacterium animalis Bb12 were the cultures employed for fermentation. Physicochemical composition, apparent viscosity, diacetyl content, viability of cultures during storage, and acceptance of product via sensorial analysis were assessment factors. The high viability of the probiotic culture was observed (average 8.08 log cfu/ml) during refrigerated storage (28 days) of buttermilk and good acceptance of the product via sensory test. However, the probiotic culture might have been responsible for the loss of diacetyl, a volatile compound that is a characteristic feature of the product.     

Physicochemical and sensory quality of several commercial Brazilian chocolate milk beverages

Five brands of Brazilian chocolate milk were subjected to physicochemical and acceptability analysis. The moisture content, fat content, pH and soluble solids content varied between 78.35 and 84.27 g/100 mL, 1.68 and 3.08 g/100 mL, 7.11 and 7.44, 14.0 and 19.0° Brix, respectively, while the ash contents and % lactic acid equivalents were similar. Four of the tested brands had acceptable scores in all attributes; however, one had lower acceptability scores and lower values for luminosity, chromaticity, b* and hue angle, which are potential indicators of the sensory quality. Strong chocolate aroma, strong chocolate flavour, strong brown colour, brightness and sandiness may be used as indicators of low acceptability for chocolate milk.     

Short communication: Effect of the addition of Bifidobacterium monocultures on the physical,chemical, and sensory characteristics of fermented goat milk

The aim of the study was to use 3 monocultures of Bifidobacterium (Bifidobacterium animalis ssp. lactis AD600, Bifidobacterium animalis ssp. lactis BB-12, and Bifidobacterium longum AD50) in fermented goat milk to assess the microbial, physicochemical, rheological, and sensory quality of beverages during a 3-wk storage period at 5°C. The results indicated that selected bifidobacteria may be used for production of fermented goat milk because they comply with the minimum standards specified by the Food and Agriculture Organization of the United Nations and the World Health Organization during the entire period of storage. However, goat milk fermented by Bif. longum AD50 had less than 10⁶ cfu/g after 21 d of storage. The acidity, acetaldehyde content, viscosity, and hardness of fermented goat milk beverages depended on the strain and the storage period. Sensory properties were similar and acceptable, with a tendency for the quality to be reduced with an extended storage time. Depending on the monoculture of bifidobacteria used to manufacture fermented goat milk, the product had a different pH value. Titratable acidity in all fermented goat milk increased significantly along with the time of storage. Our study has shown that monocultures of bifidobacteria had a significant effect on the content of acetaldehyde, but the lowest effect over the entire storage period was observed in goat milk fermented by Bif. animalis ssp. lactis BB-12. This sample also had the lowest viscosity values compared with other samples and the best organoleptic properties during a 3-wk storage period.     

Effect of storage time on sensory and instrumental properties of skim‐milk yoghurt obtained with microbial transglutaminase

Not many studies have examined changes in microbial transglutaminase (MTG) yoghurts during storage. In this work, yoghurts manufactured with skimmed milk and treated with MTG were evaluated in refrigerated storage for 35 days. Instrumental measurements showed that firmness, consistency and pH values in MTG yoghurt experienced a significant increase with the storage time. However, sensory measurements showed that MTG yoghurts were not affected significantly by storage time. Acid taste scores only increased significantly with storage time in the control samples. Microbial transglutaminase treatment showed a positive effect on textural properties and allowed syneresis to be prevented completely during storage.     

Comparison of volatile components in fermented soybean pastes using simultaneous distillation and extraction (SDE) with sensory characterisation

In this study, the volatile compounds in nine fermented soybean pastes were extracted and analysed by simultaneous steam distillation and extraction (SDE) and gas chromatography–mass spectrometry (GC–MS), respectively. A total of 91 volatile components were identified. The differences in volatiles were observed by applying principal component analyses (PCA) to GC–MS data sets. Most of the samples did not show apparent groupings; however, a three sample clustering (CJW, SIN and HAE) was observed for pastes made by Aspergillus oryzae inoculation. From the PCA of the sensory data, samples are primarily separated along the first PC (explained 68% of the total variance), between samples like SUJA, CHJA and SOHI with high intensities of ‘briny’, ‘soy sauce’, ‘musty’ and ‘astringent’ and the samples (CJW and SIN) with intense levels in ‘sweet-grain’, ‘sweet’ and ‘MSG’ attributes. The individual concentrations of volatile compounds such as isoamyl acetate, furfuryl alcohol, maltol, pyrazines, 1-octen-3-ol and 2-methoxy-4-vinyl phenol corresponded well to the intensities of related sensory attributes by the correlation analysis.     

Processing of bottom‐fermented gluten‐free beer‐like beverages based on buckwheat and quinoa malt with chemical and sensory characterization

Typical beer contains significant amount of gluten, and being the third most popular beverage worldwide, the commercial production of its gluten‐free form is of rising interest. This research aimed to prepare bottom‐fermented beverages from buckwheat and quinoa and to explore their physical, chemical and sensory properties. Compared with barley, the analysis of brewing attributes of buckwheat and quinoa showed a lower malt extracts, longer saccharification times, higher total protein and fermentable amino nitrogen content and higher values of the iodine test and colour. Fermentability values, the wort pH and the soluble protein content were similar for barley and buckwheat, but different for quinoa, whereas only values of viscosity and beverage pH were similar between barley and quinoa. Both beverages, especially the quinoa beverage, contained a superior level of metal cations. The fermentable carbohydrate content in the buckwheat wort was comparable to barley but lower in quinoa; however, worts derived from both pseudocereals contained predominantly glucose. The amino acid content of the buckwheat wort was similar to barley, whereas the content in the quinoa beverage was almost twice as high. The content of volatile compounds commonly associated with beer aroma was comparable between the barley and buckwheat beverage but significantly lower in the quinoa; however, the latter contained some distinctive volatile substances not found in the other beverages. The organoleptic perception of the buckwheat beverage was better than that of the quinoa, although both showed a good general acceptance. In general, buckwheat appears quite similar to barley, whereas quinoa shows many unique properties. Copyright © 2014 The Institute of Brewing & Distilling     

Effect of somatic cell count in goat milk on yield, sensory quality, and fatty acid profile of semisoft cheese

This study investigated the effect of somatic cell count (SCC) in goat milk on yield, free fatty acid (FFA) profile, and sensory quality of semisoft cheese. Sixty Alpine goats without evidence of clinical mastitis were assigned to 3 groups with milk SCC level of <500,000 (low), 500,000 to 1,000,000 (medium), and 1,000,000 to 1,500,000 (high) cells/mL. Thirty kilograms of goat milk with mean SCC levels of 410,000 (low), 770,000 (medium), and 1,250,000 (high) cells/mL was obtained for the manufacture of semisoft cheese for 2 consecutive weeks in 3 lactation stages. The composition of milk was analyzed and cheese yield was recorded on d 1. Cheese samples on d 1, 60, and 120 were analyzed for total sensory scores, flavor, and body and texture by a panel of 3 expert judges and were also analyzed for FFA. Results indicated that milk composition did not change when milk SCC varied from 214,000 to 1,450,000 cells/mL. Milk with higher SCC had a lower standard plate count, whereas coliform count and psychrotrophic bacteria count were not affected. However, milk components (fat, protein, lactose, casein, and total solids) among the 3 groups were similar. As a result, no significant differences in the yield of semisoft goat cheeses were detected. However, total sensory scores and body and texture scores for cheeses made from the high SCC milk were lower than those for cheeses made from the low and medium SCC milks. The difference in milk SCC levels also resulted in diverse changes in cheese texture (hardness, springiness, and so on) and FFA profiles. Individual and total FFA increased significantly during ripening, regardless the SCC levels. It is concluded that SCC in goat milk did not affect the yield of semisoft cheese but did result in inferior sensory quality of aged cheeses.     

Reduction of sodium and increment of calcium and ω‐3 polyunsaturated fatty acids in dry fermented sausages: effects on the mineral content,lipid profile and sensory quality

BACKGROUND: A combined technological approach was applied in the development of healthier dry fermented sausages: a partial substitution of the pork back fat by pre‐emulsified linseed oil and a partial replacement of sodium chloride with calcium ascorbate at two different levels, leading to low amounts of salt (14gSalt and 10gSalt, with 14 g and 10 g NaCl per kg of mixture, respectively). RESULTS: The developed products (14gSalt and 10gSalt) showed adequate results for a_w (0.85 and 0.87) and pH (4.98 and 5.21), and low lipid oxidation values (1.4 × 10^?4 and 1.5 × 10^?5 g malondialdehyde (MDA) kg^?1). The lipid modification led to a significantly higher supply of ω‐3 (23.3 g kg^?1) compared to the control (3.2 g kg^?1). Simultaneously, reductions of 38% and 50% in sodium content and a calcium supply of 4 and 5.2 g kg^?1 were achieved in the 14gSalt and 10gSalt formulations, respectively, compared to the control products (26 g salt and 0.87 g kg^?1 Ca). Instrumental analysis of colour and texture and sensory studies demonstrated that the organoleptic quality of the new formulations was similar to that of traditional products. CONCLUSIONS: The developed dry fermented sausages showed healthier properties than traditional ones owing to their reduced sodium and higher calcium content and a significant supply of ω‐3 fatty acids. © 2012 Society of Chemical Industry     

Influence of sorghum grain type on wort physico‐chemical and sensory quality in a whole‐grain and commercial enzyme mashing process

To determine the most suitable types of sorghum for whole‐grain adjunct in lager beer brewing, 14 cultivars of five different types: white tan‐plant, white non‐tan‐plant, red non‐tannin, white tannin (type II) and red tannin (type III) were evaluated. The effects of grain type on wort physico‐chemical and sensory quality with raw grain and malt plus commercial enzyme mashing were assessed. Tannin content correlated significantly and negatively with wort extract and fermentable sugars (p < 0.001) and free amino nitrogen (FAN; p < 0.1). This is attributable to inactivation of the exogenous enzymes by the tannins during the mashing process. However, the type II tannin sorghums had wort quality attributes closer to the non‐tannin sorghum types, probably owing to their relatively low tannin content (≤1%). Malting gave a great improvement in wort extract, fermentable sugars and FAN, but substantially influenced wort sensory properties in terms of higher sourness, bitterness and astringency, as well as the expected more malty flavour. Worts from raw red non‐tannin sorghums were similar to those of white tan‐plant sorghums in both physico‐chemical and sensory quality. Thus, red non‐tannin sorghums, in view of their better agronomic quality, have considerable potential as a whole‐grain adjunct in lager beer brewing. Copyright © 2013 The Institute of Brewing & Distilling     

Application of proteomics to the areas of milk production,processing and quality control – A review

Milk contains a complex mixture of proteins that undergo several qualitative and quantitative changes during processing and storage. Elucidation of these changes is important to optimise milk processing and storage parameters. Proteomics has become widely used in the field of research on milk proteins due to improvements in the tools and diversified ways in which the methodologies of protein analysis have been developed. This review describes the use of proteomics in studies on milk proteins in relation to species–species differences, post‐translational modification, effect of lactation, mastitis, changes in heated milk and during cheese ripening, and the detection of milk adulteration.