菊粉对绿豆蛋白低脂植物酸奶品质的影响

本研究考察菊粉作为脂肪替代物对绿豆蛋白低脂植物酸奶品质的影响。以添加3%葵花籽油的绿豆蛋白酸奶作为高脂酸奶对照,通过分析不同浓度的菊粉（2%、4%、6%）对绿豆蛋白低脂酸奶（1%葵花籽油）的粘弹性、质构、持水力、微观结构及感官品质的影响,评价菊粉的代脂效果。结果表明,与对照绿豆蛋白高脂酸奶相比,添加2%菊粉的绿豆蛋白低脂植物酸奶的粘弹性、硬度、咀嚼性、持水力和感官品质与绿豆蛋白高脂酸奶相当（P>0.05）,表现出均匀致密的蛋白质网络结构。添加4%菊粉的绿豆蛋白低脂酸奶的硬度和咀嚼性分别显著提高了21.56%和32.34%（P<0.05）,持水能力达到88.55%。此时,绿豆蛋白低脂酸奶也表现出致密的网络结构,整体的感官品质最佳。添加6%菊粉的绿豆蛋白低脂酸奶的粘弹性、硬度、咀嚼性和持水力显著高于绿豆蛋白高脂酸奶（P<0.05）,但是其微观结构表现出多孔以及不均匀的蛋白质网络结构,质地和口感变差,总体感官品质最差。因此,添加2%~4%的菊粉能够显著提升绿豆蛋白低脂酸奶的品质,具有较好的脂肪替代效果。本研究结果为研发高品质的绿豆蛋白低脂酸奶提供理论依据。     

草莓汁对低脂酸奶品质的影响

利用草莓汁作为脂肪替代物,研究草莓汁对低脂酸奶品质改善的影响。草莓汁按照10%、20%和30%比例加入到低脂酸奶,可使低脂酸奶的酸度升高,提高低脂酸奶硬度、黏度和持水率,降低脱水收缩率。但30%添加量会使草莓低脂酸奶结构稍松散,有明显乳清析出。感官评价上,草莓汁可使低脂酸奶具有更好的持水性,因此具有比全脂酸奶更好的口感。同时,草莓汁的添加弥补了低脂酸奶气味不足的缺点。     

乳清分离蛋白与燕麦β-葡聚糖作为增稠剂在酸奶中的应用

将乳清分离蛋白(WPI)与燕麦β-葡聚糖(β-G)以不同比例混合,热处理后添加到酸奶中,研究乳清分离蛋白/燕麦β-葡聚糖热复合物对酸奶理化、质构及感官特性的影响。分别与单独添加WPI、聚合乳清蛋白(PWP)及β-葡聚糖的酸奶样品比较,考察了酸奶的pH值、总可溶性固形物、蛋白和脂肪质量分数、质构、黏度、持水力和感官特性等指标。结果表明,WPI/β-G比例为30∶1,pH值为7.0,85℃条件下加热30 min时得到的复合物,以质量分数为2%的添加量制备酸奶,其黏度、硬度、持水力较高,感官评价较好。综合研究发现,WPI/β-G复合物可有效改善酸奶的凝胶特性及相关的理化指标,增加了酸奶的口感、风味及组织状态,提高了酸奶的品质。     

肉桂醛添加方式对乳清浓缩蛋白凝胶特性的影响

利用乳液和微胶囊的包载改善肉桂醛的亲水性,并将其添加至浓缩乳清蛋白溶液中,利用热诱导形成乳清浓缩蛋白凝胶,表征凝胶的流变特性、持水性、质构及微观结构,探究肉桂醛添加方式对所得凝胶特性的影响。结果表明,添加肉桂醛后,蛋白质凝胶的持水力显著增加。以乳液形式添加时,肉桂醛含量与凝胶的黏弹性、持水力、质构特性和网络结构的致密性呈正相关;以微胶囊形式添加时,肉桂醛可显著增强凝胶的黏弹性、持水力、质构特性和网络结构的致密性,但肉桂醛含量变化对凝胶特性的影响较小。对比两种添加方式,肉桂醛以微胶囊形式添加更能有效地调控蛋白凝胶的持水性和质构特性。     

柑橘纤维在低脂肉制品中的应用研究

以柑橘纤维作为脂肪替代物生产低脂香肠,采用传统高脂肪香肠的加工方法进行加工,在各组样品中添加不同含量(2%、3%、4%)的柑橘纤维,测定各组香肠的脂肪含量、蛋白质含量、pH、持水力、成品质构(硬度、咀嚼性、弹性、内聚性)及感官评价,并与传统高脂肪香肠进行对比分析.结果显示:当柑橘纤维的添加量为2%时,低脂香肠的脂肪含量明显降低,蛋白质含量高于传统香肠,并且在pH、持水力、成品质构(硬度、咀嚼性、弹性、内聚性)和感官评价等方面与传统香肠均无显著性差异(P>0.05),进而确定柑橘纤维作为传统高脂肪香肠中脂肪替代物的最佳添加量为2%.     

乙醇和芦丁稳定的乳清分离蛋白-大豆油预乳化液在低脂肉丸中的应用

研究乙醇和芦丁稳定的乳清分离蛋白-大豆油预乳化液作为脂肪替代物对低脂肉丸品质的影响。通过测定预乳化液的乳化稳定性、质构、黏度、粒径及流变特性，选择预乳化的最佳大豆油含量；以25%、50%、75%和100%比例对肉丸中的脂肪进行替代，以未替代的肉丸为对照组，通过测定蒸煮损失、色差、质构、气味、黏度、感官及抗氧化性，确定肉丸的最佳脂肪替代比例。结果表明：大豆油含量为72%的预乳化液乳化稳定性最好，凝胶形态良好且具有最大黏度；大豆油含量超过72%时，预乳化液的粒径增大，弹性模量下降；与对照组相比，脂肪替代比例为25%肉丸的蒸煮损失、色差（ΔE）、质构、黏度及感官得分均无显著变化，且氮氧化物、甲基类、硫化物等没有增加；贮藏9 d时，添加脂肪替代物的各组样品的硫代巴比妥酸反应物值显著低于未添加组（P＜0.05）。因此，含大豆油72%的乳清分离蛋白预乳化液作为脂肪替代物最佳，肉丸中脂肪替代比例25%效果最好。     

芝麻酚对鱼油酸奶品质及氧化稳定性的影响

摘 要：目的 开发含二十二碳六烯酸(docosahexaenoic acid, DHA)鱼油的强化型酸奶，探究芝麻酚对鱼油酸奶品质及氧化稳定性的影响。方法 将含芝麻酚的鱼油乳液应用于发酵酸奶中，通过分析酸奶的感官评价、pH、持水力、质构特性、流变特性、自由基清除活性、脂质氧化产物和DHA保留率的变化，探究芝麻酚对鱼油强化酸奶发酵品质和氧化稳定性的影响。结果 鱼油乳液的添加对酸奶的pH和自由基清除活性无显著性影响，但降低了感官评价、持水力、硬度、4℃恒温粘度、储能模量、损耗模量和4~30℃变温粘度，加速了脂质氧化。芝麻酚的添加未显著改变含鱼油酸奶的pH，增加了感官评价、持水力、硬度、4℃恒温粘度、储能模量、损耗模量和4~30℃变温粘度，提高了自由基清除活性、脂质氧化稳定性和DHA保留率(81.19%)。结论 添加300 μM芝麻酚显著改善鱼油酸奶的品质，并提高了酸奶的抗氧化功效，为DHA酸奶产品的开发提供了理论参考。     

乳清蛋白粉对凝固型酸奶品质的影响

为提高凝固型酸奶的品质及安全性,将1%、1.5%、2%、2.5%、3%、4%、5%乳清蛋白粉(Whey protein powder,WPP)加入全脂乳粉中生产酸奶,以不添加WPP的凝固型酸奶为对照组,测定酸奶酸度、持水力(WHC)、脱水收缩敏感性(STS)、质构特性、流变学特性和微观结构变化,并进行感官评定,研究不同添加量乳清蛋白粉对凝固型酸奶品质特性的影响,以确定WPP最适添加量。结果表明:随着乳清蛋白粉添加量的增加,酸奶的滴定酸度、持水力、乳酸菌总数、硬度、胶着性、粘弹性、凝胶性逐渐增加,脱水收缩敏感性(STS)逐渐减小;当WPP添加量为2%时,酸奶的持水力、粘弹性都明显提升,STS明显降低,且具有较好的口感、更连续的网络结构,与对照组相比综合品质得到明显提高。     

改性乳清蛋白对凝固型酸奶品质及胆酸盐结合能力的影响

本研究利用酶结合苹果酸复合改性乳清蛋白（WPI-E+MA）,添加至凝固型酸奶,以期改良凝固型酸奶质构及胆盐结合能力。通过蛋白质浓度、持水力、游离巯基、粒径、粘弹性及胆酸盐结合能力等指标,评价WPIE+MA对凝固型酸奶品质、凝胶结构及胆酸盐结合能力的影响。结果表明,WPI-E+MA能够改善凝固型酸奶的持水力、表观粘度、剪切应力与粘弹性,8%添加量时达到最优;酸奶的凝胶网状交联结构因WPI-E+MA的添加变得更加致密、聚合度更高。脱氧胆酸钠（SDC）、胆酸钠（SC）、牛磺胆酸钠（STC）结合率均在8%的添加量达到最大值,结合能力良好。WPI-E+MA可有效改善凝固型凝固型酸奶的品质并显著提高胆酸盐结合能力。     

豌豆淀粉对脱脂乳酶凝特性及对加工低脂干酪品质的影响

为了探究豌豆淀粉作为脂肪替代物对契达干酪品质的影响,以牛乳凝乳特性为指标,分析豌豆淀粉、浓缩乳清蛋白和菊粉作为脂肪替代物的差异优势。然后将与牛乳脂肪球结构相似的豌豆淀粉(尺寸2～40μm)添加到低脂乳(脂肪含量1.5%)和脱脂乳(脂肪含量0.5%)中,制备低脂和脱脂契达干酪,探究其对牛乳凝乳特性和干酪品质的影响。再以全脂契达干酪为对照,比较分析3组干酪在成熟期组成成分、蛋白水解度、质构及感官特性的差异。结果表明,当脂肪替代物添加量为1.0%～3.0%(w/w)时,豌豆淀粉组凝乳时间(40～43 min)、凝乳强度(0.83～0.95 N)、凝乳得率(10.1%～11.9%)、乳清OD值(0.766～0.892)均显著(P0.05)优于乳清蛋白组和菊粉组。豌豆淀粉在低脂、脱脂乳中分别添加1%和2%(w/w)时,凝乳效果最佳。与全脂干酪相比,低脂和脱脂干酪的蛋白质含量分别增加2.26%、4.14%,脂肪含量分别下降15.42%、26.87%,但脱脂干酪蛋白质水解度显著低于全脂干酪(P0.05);2组干酪的W/P值、硬度、弹性、内聚性、外观色泽与全脂对照组无显著性差异(P0.05),且豌豆淀粉低脂组总体感官评分与全脂对照组差异不显著(P0.05)。     

Application of whey protein emulsion gel microparticles as fat replacers in low-fat yogurt: Applicability of vegetable oil as the oil phase

Low-fat, healthy yogurt is becoming increasingly favored by consumers. In the present study, whey protein emulsion gel microparticles were used to improve the quality of low-fat yogurt, and the effects of vegetable oil emulsion gel as a fat substitute on the qualities of low-fat yogurt were investigated, expecting to obtain healthier and even more excellent quality low-fat yogurt by applying a new method. First, emulsion gel microparticles were prepared, and then particle size distribution of emulsion gel and water holding capacity (WHC), textural properties, rheological properties, microstructure, storage stability, and sensory evaluation of yogurt were carried out. The results showed that yogurt with emulsion gel had significantly superior qualities than yogurt made with skim milk powder, with better WHC, textural properties, rheological properties, and storage stability. The average particle size of whey protein-vegetable oil emulsion gel microparticles was significantly larger than that of whey protein-milk fat emulsion gel microparticles, and the larger particle size affected the structural stability of yogurt. The WHC of yogurt made with whey protein-vegetable oil emulsion gel microparticles (V-EY) was lower (40.41%) than that of yogurt made with whey protein-milk fat emulsion gel microparticles (M-EY; 42.81%), and the texture results also showed that the hardness, consistency, and viscosity index of V-EY were inferior to these of M-EY, whereas no significant differences were found in the cohesiveness. Interestingly, the microstructure of V-EY was relatively flatter, with more and finer network branching. The whey separation between V-EY and M-EY also did not show significant differences during the 14 d of storage. Compared with yogurt made with whey protein, vegetable oil, and skim milk powder, the structure of V-EY remained relatively stable and had no cracks after 14 d of storage. The sensory evaluation results found that the total score of V-EY (62) was only lower than M-EY (65) and significantly higher than that of yogurt made with skim milk powder. The emulsion gel addition improved the sensory qualities of yogurt. Whey protein emulsion gel microparticles prepared from vegetable oil can be applied to low-fat yogurt to replace fat and improve texture and sensory defects associated with fat reduction.     

高蛋白无脂肪酸奶的研制

以凝胶型乳清浓缩蛋白80、微粒化乳清蛋白和淀粉脂肪替代物的组合作为脂肪替代品用于替代酸奶中的脂肪,得到了3种配料的最优比例,从而从质构、口感、风味角度成功模拟了酸奶中脂肪的作用,成功开发出一款高蛋白、零脂肪的健康酸奶。     

The influence of added whey protein/carrageenan gels and tapioca starch on the textural properties of low fat pork sausages

Response surface methodology (RSM) was used for simultaneous analysis of the effects of added high gelling 35% whey protein concentrate, (0-12%)/carrageenan (0-3%) preformed gels with dry addition of tapioca starch (0-3%), on the physical, textural and sensory characteristics of low-fat fresh pork sausages. Experimental design allowed for evaluation of potential interactive effects between these ingredients. Sausages were evaluated for cookloss, water holding capacity (WHC), mechanical texture and sensory attributes. Analysis of variance of regression models showed that ingredient blends had a significant influence on cookloss (p<0.01), WHC (p<0.05), purgeloss (p<0.05), texture (p<0.001) and the sensory attributes of flavour intensity (p<0.05), overall flavour (p<0.01) and juiciness (p<0.001). Addition of preformed gel and tapioca starch had a significant (p<0.01) negative interactive effect on % cook loss, and gave a significant (p<0.05) positive linear effect for mechanical textural values. Increasing levels of preformed gel blends with tapioca starch resulted in a general decrease in flavour intensity and overall flavour scores. Mixed gels containing high gelling 35% (protein) whey protein concentrate (8%) and carrageenan (1.5%), with dry addition of tapioca starch (3%) produced final low-fat (<3% fat) pork sausages with similar characteristics to those of full-fat (20% fat) controls.     

FAT REPLACERS IN LOW-FAT MEXICAN MANCHEGO CHEESE

Low-fat Manchego cheeses (15 g fat/L milk) were prepared with three commercial fat replacers consisting of low methoxyl pectin (LMP), whey protein concentrate (WPC) and microparticulated whey protein (MWP). A low-fat cheese (15 g fat/L milk) without added fat replacer and a full-fat cheese (30 g fat/L milk) were prepared as controls. Cheeses were matured thirty days prior to instrumental texture profile analysis, microstructure analysis, and discriminative sensory evaluation. Scanning electron micrographs showed that the low-fat cheeses incorporating the LMP and WPC fat replacers lost the compact and dense protein matrix characteristic of the low-fat control cheese and exhibited hardness, springiness, cohesiveness and chewiness similar to the full-fat control cheese. No significant difference was found in the sensory characteristics between the full-fat control cheese and the cheese incorporating WPC.     

Influence of fat replacers on chemical composition, proteolysis, texture profiles, meltability and sensory properties of low-fat Kashar cheese

Changes in chemical composition, proteolysis, lipolysis, texture, melting and sensory properties of low-fat Kashar cheese made with three different fat replacers (Simplesse D-100, Avicel Plus CM 2159 or beta-glucan) were investigated throughout ripening. The low-fat cheeses made with fat replacers were compared with full- and low-fat counterparts as controls. Reduction of fat caused increases in moisture and protein contents and decreases in moisture-in-non fat substance and yield values in low-fat cheeses. The use of fat replacers in the manufacture of low-fat Kashar cheese increased water binding capacity and improved overall quality of the cheeses. Use of fat replacer in low-fat cheese making has enhanced cheese proteolysis. All samples underwent lipolysis during ripening and low-fat cheeses with fat replacers had higher level of total free fatty acid than full- or low-fat control cheeses. Texture attributes and meltability significantly increased with addition of fat replacers. Sensory scores showed that the full-fat cheese was awarded best in all stages of ripening and low-fat variant of Kashar cheeses have inferior quality. However, fat replacers except beta-glucan improved the appearance, texture and flavour attributes of low-fat cheeses. When the fat replacers are compared, the low-fat cheese with Avicel Plus CM 2159 was highly acceptable and had sensory attributes closest to full-fat Kashar cheese.     

不同大豆原料对豆清发酵液豆腐和卤水豆腐加工特性的影响

以黑龙48、临豆10号、临豆9号、齐黄34、华豆2号及华豆10号6种不同大豆品种为原料,根据豆腐生产的基本工艺,分别以豆清发酵液、盐卤(MgCl₂)作为凝固剂生产豆腐。通过感官评价、产品得率、保水性、质构特性、蛋白质、脂肪及水分含量等指标进行分析,探讨不同大豆原料对豆清发酵液豆腐和卤水豆腐加工特性的影响。研究结果表明:6种不同大豆原料所产的豆腐感官评价、产品得率、保水性、质构特性、蛋白质、水分及脂肪含量差异均达极显著水平(p<0.01)。其中华豆2号、临豆10号、临豆9号和齐黄34的豆清发酵液豆腐的得率、保水性、质构参数较高,最高为华豆2号,其得率、保水性、硬度、弹性、耐嚼性的指标分别高达176.532%、72.155%、174.482 g、0.778 mm、64.530;齐黄34、华豆2号、华豆10号、临豆10号的卤水豆腐得率、保水性、质构参数较高,最高为齐黄34,其得率、凝聚性、弹性等指标依次为188.879%、2.951、0.789 mm。综合感官评价及蛋白质等营养指标,分析得出华豆2号、临豆10号、临豆9号和齐黄34较适生产豆清发酵液豆腐,齐黄34,华豆2号、华豆10号、临豆10号较适加工卤水豆腐。     

Structural properties of stirred yoghurt as influenced by whey proteins

The effect of whey protein addition on structural properties of stirred yoghurt systems at different protein and fat content was studied using laser diffraction spectroscopy, rheology and confocal laser scanning microscopy (CLSM). The composition of heated milk systems affected micro- and macroscopic properties of yoghurt gels. Particle size increased as a function of increasing whey protein content and decreased as a function of increased fat level. Firmness (elastic modulus) and apparent viscosity of manufactured yoghurt samples increased as a function of increased interparticle interactions, mainly caused by self-aggregation of whey proteins or aggregated whey protein-coated fat globules, respectively. The resistance towards shear-induced disruption of yoghurt gels increased with an increasing proportion of casein protein in the protein mixture, whereas products with high whey protein level revealed lower resistance behaviour towards shear-forces. CLSM images illustrated that the presence of large whey protein aggregates and lower number of fat globules lead to the formation of an interrupted and coarse gel microstructure characterised by large interstitial spaces. The higher the casein fraction and/or the fat level, the less interspaced voids in the network were observed. However, it is evident that the addition of whey proteins reinforces firmness properties of low-fat yoghurts comparable to characteristics of full-fat yoghurt.     

The effect of using a whey protein fat replacer on textural and sensory characteristics of low-fat vanilla ice cream

The purpose of this research was to evaluate the texture of regular (12%), low fat (6%), and fat-free vanilla (0.5%) ice creams by sensory and instrumental analyses. The low fat and fat free ice cream were prepared using a whey protein based fat replacer (Simplesse ^® 100) as the fat replacement ingredient. Two processing trials with continuous commercial-like process conditions were undertaken. Sensory analyses disclosed that ice creams containing 6% of fat replacer in place of or with milk fat had no demonstrable effect on vanillin flavour. While the sensory attributes of the low fat samples were comparable to the regular vanilla ice cream, the trained sensory panel rated the fat free ice cream to have lower viscosity, smoothness and mouth coating properties. Instrumentally determined apparent viscosity data supported the sensory data. Compared with the fat replacer, milk fat significantly increased the fresh milk and cream flavours of the ice cream. Results emphasized the importance of fat as a flavour modifier and the improvement of texture by addition of Simplesse ^® 100.     

Effects of various whey proteins on the physicochemical and textural properties of set type nonfat yoghurt

In this study, the changes during storage in the physicochemical, textural and sensory properties of nonfat yoghurts fortified with whey proteins, namely whey protein concentrates (WPC), whey protein isolates and whey protein hydrolysates, were investigated. Enrichment of nonfat yoghurt with the whey protein additives (1% w/v) had a noticeable effect on pH, titratable acidity, syneresis, water‐holding capacity, protein contents and colour values on the 14th day of storage (P < 0.01). The addition of whey proteins to the yoghurt milk led to increases in the hardness, cohesiveness and elasticity values, resulting in improved textural properties. The addition of WPC improved the texture of set‐type nonfat yoghurt with greater sizes in the gel network as well as lower syneresis and higher water holding capacity. This study suggests that the addition of whey protein additives used for fortification of yoghurt gave the best textural and sensory properties that were maintained constant during the shelf life.