Comparative aroma and taste profiles of oil furu (soybean curd) fermented with different mucor strains

The effects of different mucor strains (Mucor racemosus, Actinomucor, and Mucor wutungkiao) on aroma and taste profiles based on proteolysis, lipolysis, and their catabolism in oil furu were studied. Gas chromatography-mass spectrometry and relative odor activity were used to monitor the changes of key volatile compounds and the differences in the characteristic aroma contents of oil furu. Using principal component analysis, the different fermentation strains had an effect on aroma profiles. The volatile compounds from metabolism of protein and fatty acid contributed to the aroma of oil furu with different contribution from the different strains, presumably due to their different enzymes. The electronic tongue and free amino acid profiles also showed strain differences of taste. Based on these results, optimization of the amount of each of the different mucor strains during cofermentation might achieve better flavor.     

云南腐乳发酵菌种的分离鉴定及其低盐腐乳的品质分析

对云南牟定腐乳中的霉菌进行分离纯化,获得适用于腐乳发酵的菌种,并将其应用于低盐腐乳生产中,探讨低盐发酵对腐乳品质的影响。通过形态学和分子生物学鉴定筛选菌种;采用标准法、扫描电子显微镜、顶空固相微萃取-气质联用技术和感官评价分别分析了低盐腐乳的理化性质、微观结构、挥发性风味成分和感官品质。从腐乳前发酵毛坯中分离纯化获得了白色的优质总状毛霉(M2)并应用于低盐腐乳的制备;随着盐含量的降低,腐乳中总酸、氨基酸态氮、水溶性蛋白、游离氨基酸含量逐渐升高,蛋白质水解程度逐渐增大,腐乳凝胶孔径逐渐缩小,结构更加致密均一。低盐腐乳中共检测出了45种挥发性风味物质,且盐含量对挥发性风味物质含量有较大影响,感官评定结果表明,盐含量对腐乳的滋味和质地影响较大,且M2-70%的接受度最高。实验所获得的总状毛霉适用于云南腐乳的发酵,适当的低盐发酵可提高腐乳的品质。     

Effect of a beating process,as a means of reducing salt content in Chinese-style meatballs (kung-wan): A physico-chemical and textural study

Two different meat-cutting methods were used to prepare kung-wans in an attempt to produce low-salt products while retaining the same, or improved, textural and physicochemical properties of the standard high-salt formulation. The level of salt and the processing method significantly affected color, cooking yield, texture and changes in the secondary structures of proteins. Improved salt levels resulted in firmer texture. At the same salt levels, compared with chopping, the beating method resulted in higher L^?-values, improved cooking yields and changes in the β-sheet content of the proteins, which resulted in an improved product with better texture. Using the beating process, the kung-wans prepared with 1% and 2% salt had similar L^?-values, cooking yield and texture, and were better than those prepared by chopping with 2% salt. Overall, the beating process enabled lowering of the salt content, making the kung-wans more hard, brittle and elastic.     

Evaluation of various salt levels and different dairy proteins in combination with microbial transglutaminase on the quality characteristics of restructured pork ham

The objective of this study was to evaluate the quality characteristics of restructured pork hams (RH) manufactured with various salt levels (0.5%, 1.0%, and 1.5%) and different dairy proteins (sodium caseinate, SC and whey protein isolate, WPI; 1.0%) in combination with microbial transglutaminase (MTGase; 0.3%). Reduced‐salt (0.5% and 1.0%) RH resulted in reductions of moisture contents (%), textural springiness, cooking yield and most sensory preferences (P < 0.05). When dairy proteins in combination with MTGase were incorporated into the manufacture of RH, SC with MTGase was shown to reduce cooking loss (CL, %) and to increase the textural springiness and chewiness of RH, whereas WPI with MTGase increased textural springiness and chewiness, as well as the shear value of RH (P < 0.05). On the contrary, MTGase with dairy proteins improved the sensory preferences of reduced‐salt (1.0%) RH to give it similar sensory properties to those of the regular‐salt (1.5%) RH controls (CTL) (P > 0.05). The findings of this study demonstrated that the combination of 1.0% dairy proteins and 0.3% MTGase could affect improvements in the functional, textural and sensory properties of reduced‐salt (1.0%) RH.     

Effect of NaCl on textural changes and protein and lipid degradation during the ripening stage of sufu,a Chinese fermented soybean food

Sufu is made by solid state fungal fermentation (using Actinomucor elegans) of tofu, followed by salting and maturation in dressing mixtures containing salt, alcohol and various other ingredients. NaCl in dressing mixtures strongly affected the changes in textural properties and the hydrolysis of protein and lipid of sufu. Higher salt contents (14% w/w) resulted in increased hardness (+100%) and elasticity (+18%) and reduced adhesiveness (?30%). Hardness and elasticity could be used to judge the extent of sufu ripening. SDS‐PAGE showed the disappearance of all protein subunits at 80 and 110 g kg^?1 salt content; however, some protein subunits were still detectable at 140 g kg^?1 salt content after 60 days of ripening. Higher ratios of free amino nitrogen to total nitrogen (FAN/TN = 0.4–0.45) and free amino acids to crude protein (FAA/CP = 0.24–0.26) were observed in sufu with lower (80 g kg^?1) salt content. FAN/TN and FAA/CP in white sufu (obtained with dressing mixtures containing only salt and alcohol) were higher than those in red sufu (obtained with dressing mixtures containing angkak or kojic red rice) owing to different dressing mixture compositions. Increases in free fatty acids (FFA) were also observed during ripening. FFA levels in sufu with lower salt content increased rapidly during the first 30–40 days and then increased slowly, probably resulting from the formation of fatty acid esters. Lowering the salt content (80 g kg^?1) can shorten the ripening time to 40 days, which is of benefit to manufacturers. However, sufu will spoil, ie undergo souring, during the ripening stage at salt contents of 50 g kg^?1 or lower. Copyright © 2003 Society of Chemical Industry     

Effects of high pressure level and holding time on properties of duck muscle gels containing 1% curdlan

The effect of high pressure processing (HPP) on properties of duck muscle gels (DMG) containing 1% curdlan was investigated. The application of > 300 MPa could result in the decrease of cooking loss of DMG in water binding capacity, the increase of L value and the decrease of a value and b value in color, the increase of hardness, springiness, cohesiveness and chewiness in textural parameters (P < 0.05), while the pressure-holding time had no obvious influence. Those experimental results could be attributed to the interactions among protein molecules and the interactions between protein molecules and curdlan molecules created or enhanced by HPP. Overall, the use of curdlan instead of fat and the application of HPP may provide a novel approach to achieve low-fat (< 6% fat) and low-salt (1% salt) DMG products with good properties and high yields.

Industrial relevance

To provide healthier meat foods like low-fat (< 6% fat) and low-salt (about 1% salt) duck meat products, the application of HPP might be of great interest for industrial manufacture and can yield the products bearing high water binding capacity and good textural properties.     

Effects of rice koji inoculated with Aspergillus luchuensis on the biochemical and sensory properties of a sailfin sandfish (Arctoscopus japonicus) fish sauce

The effects of rice koji inoculated with Aspergillus luchuensis on the biochemical and sensory properties of fish sauce produced from sailfin sandfish (Arctoscopus japonicus) with different salt concentrations (10% and 20%) were investigated over 10 months. Fish sauces prepared from sailfin sandfish with rice koji and a low salt concentration had higher total nitrogen, amino nitrogen and total free amino acid than did those without rice koji or with a high salt concentration. Sensory evaluation of fish sauces prepared with rice koji and a low salt concentration found better taste, flavour and overall acceptance than those prepared without rice koji during fermentation (P < 0.05). The use of rice koji increased the total nitrogen, amino nitrogen and free amino acid and also enhanced the sensory qualities during fermentation. These results suggest that the use of rice koji can result in a low‐salt fish sauce with better flavour.     

Use of dairy proteins and microbial transglutaminase to obtain low-salt fish products from filleting waste from silver carp (Hypophthalmichthys molitrix)

Restructured fish products from the filleting waste from silver carp (Hypophthalmichthys molitrix) were obtained using sodium caseinate (1%), whey protein concentrate (WPC) (1%) or MTGase (0.3%) at different levels of salt (0%, 1% or 2%). The restructured products were obtained by incubating at 40 °C for 60 min and then at 90 °C for 20 min. Changes in the mechanical properties were studied by measuring changes in the textural profile analyses, punch test and torsional test analyses and expressible water. The mechanical properties increased when the salt level was also increased. The mechanical properties of non-salted and low-salt products were increased by using dairy proteins. Sodium caseinate had a greater effect in improving mechanical properties than WPC. MTGase increased expressible water. The results obtained showed that the mechanical properties of low-salt restructured fish products can be improved by using dairy proteins combined with MTGase, with a slight increase in expressible water.     

Evaluation of various salt contents on quality characteristics with or without curdlan of pork myofibrillar protein gels and the development of low-salt pork sausages

The objective of this study was to evaluate the gelling properties of pork myofibrillar protein (MP) gels at various salt concentrations with or without curdlan, and its application to model sausages with reduced salt levels. When curdlan was incorporated into MP mixtures, cooking yield (CY) at 0.15 m salt was similar to that of 0.45 m salt (P > 0.05). Gel strength of MPs at 0.45 m salt was highest among other salt concentrations. Increased salt concentration tended to be high shear stress values, regardless of the presence of curdlan (P < 0.05). MP gels with increasing salt concentration showed fewer pores and swollen structures. Addition of curdlan improved CY and expressible moisture of low-fat model sausage with increased salt levels. The addition of curdlan at 1.0% salt reduced the hardness and gumminess, and similar to those at 1.5% without curdlan. These results indicated that curdlan improved the water-holding capacity and textural properties of low-fat and low-salt sausage.     

Effects of Salts and Preheating Temperature of Brine on the Texture of Pickled Cucumbers

The effects of salt type and preheating temperature on the texture and quality of pickled cucumber were studied. Four types of salt were used: bay salt, purified salt, and 2 prepared salts, 1 containing the same amount of Ca²⁺ and Mg²⁺ as those of bay salt, and the other containing a 3‐fold higher concentration of Ca²⁺ and Mg²⁺ than bay salt. Two different temperatures were used for the salt solutions: 98 °C and 65 °C. All samples were fermented for 30 d at 25 °C. To evaluate the quality of the pickled cucumber with fermentation, the pH level, total acidity, alcohol insoluble solids, and mineral contents were analyzed. Texture and sensory evaluation as well as a microscopic observation were performed to observe the textural change of the pickled cucumber during fermentation. Pickled cucumbers with 98 °C of preheated brine showed better texture than the ones with 65 °C. The pickled cucumbers brined with prepared salt, 1 which had the same amount of Ca²⁺ and Mg²⁺ to bay salt, displayed the best result among the samples tested, in terms of sensory, textural, and physical properties.     

Novel approach for the development of dietary fibre-anthocyanin enriched functional bread from culinary banana bract

Dietary fibre (DF)-anthocyanin formulation was incorporated in bread to develop anthocyanin rich DF powder (ARDFP) fortified bread. Prior to incorporation of DF-anthocyanin formulation in bread preparation, the cytotoxicity of DF and anthocyanin extracts was assessed. The effect of incorporation of different level of ARDFP with moisture on bread quality characteristics such as specific volume, textural, colour, sensory properties and starch digestibility was studied. The results revealed that extracted DF and anthocyanin of culinary banana bracts were nontoxic towards peripheral blood mononuclear cell and cytotoxic towards HT29 cancerous cell line. Incorporation of 2% ARDFP with 68% moisture was rated as best with higher specific volume (5.50 cm³ g⁻¹), improved textural properties (high springiness and cohesiveness), anthocyanin content (9.08 mg per 100 g), colour characteristics and sensory acceptability next to control. The in vitro digestibility study suggested increased incorporation of ARDFP in bread flour reduced the rate of starch digestibility (0.0035 min⁻¹).     

降低食盐添加量对火腿肠的感官、质构及保水特性的影响

为研制低钠盐火腿肠,研究降低食盐添加量对火腿肠质量的影响。设置6个不同的食盐添加量梯度(以原料猪肉质量为基准计)：3%(对照)、2.5%、2.0%、1.5%、1.0%、0.5%,分别对产品的水分活度、保水性和质构进行测定,同时进行感官评分。结果表明：随着食盐添加量的降低,火腿肠的水分活度逐渐升高,而保水性逐渐下降;质构测定显示,产品的硬度、咀嚼度、黏聚性也随着食盐添加量的下降而降低,当食盐添加量极低时,这种下降趋势很明显,但弹性却变化不大;感官评定结果表明,随着食盐添加量的降低,火腿肠颜色变浅,切面粗糙,咸味下降,当食盐添加量降低到1.0%时不易被接受。因此,食盐对猪肉火腿肠的感官、质构和保水性等有着重要的作用,本研究为进一步调整配方开发低钠盐火腿肠提供了重要参考。     

Effect of microbial transglutaminase, sodium caseinate and non-fat dry milk on quality of salt-free, low fat turkey döner kebab

Effects of microbial transglutaminase (MTGase) and its combinations with sodium caseinate (SC) or non-fat dry milk (NFDM) on quality of salt-free, low fat turkey döner kebab were investigated. The purpose of this study was to prevent quality deteriorations (e.g. cooking loss, textural problems) caused by a lack of salt in the product. The results of this study indicated that the use of MTGase can minimize textural quality loss caused by a lack of salt in turkey döner manufacture (p < 0.05). When the enzyme was combined with SC, or NFDM, its effect on texture was enhanced (p < 0.05) and improved cooking yield, moisture and sensory properties compared to the corresponding control manufactured without the enzyme, salt, SC and NFDM. (p < 0.05), however, there was no significant effect on pH and color As a result, the possible quality problems which may occur in salt free, low fat turkey döner can be overcome by the use of combinations of MTGase with SC or NFDM.     

Evaluation of the effect of salts on chemical,structural, textural,sensory and heating properties of cheese: Contribution of conventional methods and spectral ones

ABSTRACT

Chemical composition, sensory characteristics, textural and functional properties are among the most important characteristics, which directly relates to the global quality of cheese and to consumer acceptability. A number of factors including milk composition, processing conditions and salt content, influences these properties. The past decades many investigations were performed on the possibilities to reduce salt content of cheese due to its adverse health effects, the current lifestyle and the awareness of the consumers for nutrition quality products. Due to the multiple potential effects of reducing NaCl (simple reduction or substitution) on cheese attributes, it is of utmost importance to identify and understand those effects in order to control the global quality and safety of the final product.

In the present review a collection of the different results and conclusions drawn after studying the effect of salts by conventional (e.g. wet chemistry) and instrumental (e.g. spectral) methods on chemical, structural, textural, sensory and heating properties of cheese are presented.     

Quality characteristics of low-fat chicken nuggets: effect of common salt replacement and added bottle gourd (Lagenaria siceraria L.)

BACKGROUND: There is growing demand for the meat products having healthier characteristics. In an endeavour to develop low‐salt, low‐fat and high‐fibre chicken nuggets an investigation was carried out to observe the effects of partial replacement (40%) of sodium chloride in pre‐standardised low‐fat chicken nuggets (Control, 20 g kg^?1 NaCl) with a salt substitute blend as well as incorporation of bottle gourd (Lagenaria siceraria L.) in the resulting low‐salt, low‐fat products at three different levels, i.e. 50, 75 and 100 g kg^?1 (Treatments, 12 g kg^?1 NaCl) on the various quality attributes. RESULTS: Sodium chloride replacement decreased (P < 0.01) emulsion and product pH, cooking yield, moisture, ash, yellowness, hue value and textural properties. pH values, moisture and dietary fibre increased (P < 0.01) while cooking yield, % protein, textural properties and total cholesterol were decreased with the incorporation of bottle gourd in low‐salt, low‐fat nuggets. Sensory attributes of the product were not affected with salt replacement; however, inclusion of bottle gourd at higher levels decreased (P < 0.05) flavour and texture scores. CONCLUSION: The results suggest that low‐salt, low‐fat and high‐fibre chicken nuggets can be developed with the use of a salt substitute blend and bottle gourd without affecting their acceptability. Copyright © 2012 Society of Chemical Industry     

Quality evaluation of Korean soy sauce fermented in Korean earthenware (Onggi) with different glazes

The aim of this study was to investigate the effect of porosity‐controlled earthenware as fermentation vessels for Korean soy sauce. Porosity of fermentation vessels was controlled by glazing the surfaces of Korean earthenware. Three kinds of onggis– the outside glazed, inside and outside glazed, and unglazed onggi – were made and used to investigate the effect of glazing on the fermentation of soy sauce. During fermentation of soy sauce in porosity‐controlled earthenwares at 30 °C for 4 months, physical, chemical, microbiological and sensory quality attributes were monitored. Compared to other vessels, soy sauce fermented in onggi with both inside and outside surfaces glazed showed less water loss (10.7%), salt content (17.6%) and pH (pH4.4) after the fourth month. It also produced higher total acidity (1.43%), protease activity (810 μg mL^?1 min^?1) and microbiological changes that included total aerobic bacteria [4.3 log(cfu mL^?1)], lactic acid bacteria [3.8 log(cfu mL^?1)] and yeast [4.2 log(cfu mL^?1)]. The contents of total nucleotide (200–255 mg per 100 g sample) and free amino acids (4634–4848 mg per 100 g sample) in soy sauce were not consistent with glazing, which may be more affected by other factors, such as water loss, than the porosity of vessels. However, the percentage of glutamic acid among total free amino acids was 23.6% in onggi with both surfaces glazed, which was a little higher than the 21.9% in the outside glazed and 21.5% in the unglazed. These positive physicochemical and microbiological changes during fermentation in onggi with both sides glazed also resulted in higher sensory quality.     

Proteolysis,Texture, and Sensory Characteristics of Serrano Hams from Duroc and Large White Pigs during Dry‐Curing

Proteolysis, texture, physicochemical, and sensory characteristics of Serrano hams from Duroc and Large White pigs at 5, 7, 9, 12, and 15 m of curing (3 hams per breed per curing time) were investigated. Higher concentrations of some sarcoplasmic and myofibrillar proteins, peptides with molecular mass in the ranges 3700 to 12000 Da, 700 to 2000 Da, and below 450 Da, and total free amino acids were recorded for Large White hams, while hydrophobic peptides were at higher levels in Duroc hams. A 40 kDa peak in the low‐ionic‐strength soluble protein fraction and 2 peaks of 40 and 45 kDa in the high‐ionic‐strength soluble protein fraction found only in Duroc hams could be of use in discriminating products from different breeds. Physicochemical and textural characteristics of both types of hams evolved similarly during curing and differences in organoleptic traits between breeds were negligible. Flavor intensity and flavor quality of hams were strongly correlated to curing time, with r² values over 0.95 for flavor intensity and over 0.90 for flavor quality, and to the concentration of total free amino acids, with r² values over 0.90 for both flavor intensity and flavor quality. The sensory evaluation scores of Duroc hams, at least as high as those of Large White hams, make the production of high‐quality Serrano ham from pure breed Duroc pigs feasible. Practical Application: Duroc breed crosses are advantageous in the production of dry‐cured hams, resulting in higher marbling, enhanced flavor and lower processing losses, but the characteristics of pure breed Duroc hams have not been investigated. The similar evolution of the compositional, proteolytic, textural, and sensory characteristics of Serrano hams from Duroc and Large White pigs during dry‐curing recorded in the present work makes the production of high‐quality dry‐cured hams from pure breed Duroc pigs feasible. Three protein peaks found only in Duroc hams can be of use to discriminate products from different breeds.     

Application of selected lactic acid bacteria and coagulant for improving the quality of low-salt Cheddar cheese: Chemical,microbiological and rheological evaluation

With the aim of counteracting adverse sensory characteristics of salt reduction in Cheddar cheese, use of a glutamate decarboxylase-negative starter, camel chymosin as coagulant and Lactobacillus helveticus CHCC 4481 and Lactobacillus pentosus CHCC 13992 as adjuncts were investigated. Chemical, microbiological and rheological changes in low-salt (0.85%)/normal-moisture (37.7%) content cheeses were determined. Camel chymosin showed a large capacity for decreasing bitter peptide formation and Lb. helveticus CHCC 4481 for increasing bitter peptide degradation and for the release of flavour enhancing amino acids. An additional small amount of free Glu was gained from the use of the glutamate decarboxylase-negative starter. Lb. pentosus CHCC 13992 successfully converted all residual citrate into the flavour enhancer, succinate after 150 days of ripening. Rheological effects as determined by fracture strain (ε_H,f) and Young's modulus (E) appeared of secondary relevance in terms of quality recovery as none of the low-salt cheeses deviated from normal-salt ranges.     

Physico-Chemical,antioxidant activities,textural, and sensory properties of yoghurt fortified with different states and rates of pomegranate seeds (Punica granatum L.)

This study examines the effects of incorporating fresh, frozen, osmodehydrated, and dried pomegranate seeds, at different concentrations (5, 10, and 20%) on the physicochemical, antioxidant, textural, and sensory properties of yoghurt. Antioxidant activity, pH, acidity, syneresis, and color of yoghurt were also evaluated during the storage (28 days) at 4°C. The principal component analysis (PCA) was performed to assess the correlations between different yoghurt formulation and their sensory attributes. Data showed that the addition of pomegranate seeds reduced pH and modified the chromatics coordinate (L*, a*, b*, C*, h°) and firmness of the yoghurt samples. In addition, acidity, °Brix, and syneresis increased compared to the control. Thanks to their high anthocyanin content, pomegranate seeds considerably improved the antioxidant activity essentially for yoghurt enriched with frozen seeds. In addition, the supplementation of 20% of frozen seeds into yoghurt was the most appreciated by panelists and improved the sensory properties in comparison to other formulation. According to PCA, taste and appearance were the main criteria for the overall acceptability of yoghurt. After 28 days of storage, the reddish color was reinforced; however, the antioxidant activity of yoghurts was reduced. Overall, it can be concluded that pomegranate seeds can be used as a natural ingredient to develop a novel yoghurt with high nutritional properties.