消费者感官评价对酸奶品质提升的导向研究

消费者感官评价为产品开发和工艺改良提供实际依据。本文以酸奶为例,结合消费者感官测试完成其品质提升。分别收集消费者的基本信息,以及他们对酸奶整体喜好度、香气喜好度；香气、甜味、酸味、稠度接受度；和酸奶所需要提升的感官属性的主观建议等。结合喜好度分析、惩罚分析、词云频率等数据分析方法,得到消费者对酸奶的品评结果。实验结果表明四种酸奶的整体喜好度与香气喜好度平均值都在5分以下,说明消费者的认可度不高；且酸奶的香气与整体喜好度之间有正相关性。酸奶661和467的产品更受消费者的欢迎。由于这两者目前的喜好度分值仍较低(<5.0),需要进一步优化其配方,以期获得更好的市场价值。消费者关注的酸奶品质主要包括酸度、甜度、香气和稠度。喜好度分析和接受度惩罚分析的结果发现酸奶467是目前消费者喜好度较高的产品,后期通过降低其酸度,可以更好地提高它的接受度,从而获得更多消费者的青睐。以消费者为导向探究乳制品的风味感官品质,为产品的优化升级提供指导意义。未来通过调试酸奶的风味性质可生产出深受消费者喜爱的产品。     

Quality characteristics and consumer acceptance of yogurt fortified with date fiber

Yogurt is considered a healthy food and incorporating dietary fiber will make it even healthier. Date fiber (DF), a by-product of date syrup production, is a good source of dietary fiber. The effect of fortification with DF on fresh yogurt quality was investigated. Acidity, pH, color [L* (lightness), a* (redness), and b* (yellowness) values], texture profile, sensory properties, and consumer acceptance were studied. Control yogurt (without fiber), yogurt fortified with 1.5, 3.0, and 4.5% DF, and yogurt with 1.5% wheat bran (WB) were prepared. Fortification with DF did not cause significant changes in yogurt acidity, although pH was increased. Yogurts fortified with DF had firmer texture (higher hardness values) and darker color (lower L* and higher a*) compared with control or WB yogurts. Consumer test results indicated that the appearance, color, and flavor ratings were significantly affected by fiber fortification. Yogurt fortified with up to 3% DF had similar sourness, sweetness, firmness, smoothness, and overall acceptance ratings as the control yogurt. Sensory ratings and acceptability of yogurt decreased significantly when increasing DF to 4.5% or using 1.5% WB. Flavoring yogurt fortified with 4.5% DF with vanilla did not improve flavor or overall acceptance ratings. Thus, fortifying yogurt with 3% DF produced acceptable yogurt with beneficial health effects.     

添加益生元对酸乳凝胶过程及微观结构的影响

为研究菊粉、低聚果糖和低聚半乳糖3 种益生元对酸乳凝胶过程及微观结构的影响,以未添加益生元的酸乳为对照,利用光学微流变仪、Turbiscan稳定分析仪和扫描电子显微镜分别检测添加益生元酸乳在发酵期间及后熟贮藏期间流变学参数、稳定性和微观结构,并进行对比研究。结果表明：添加菊粉更有助于酸乳形成较为均匀、疏松的微观结构;含低聚果糖的酸乳固液平衡值低于0.5,更有利于增强酸乳的固体性质;添加低聚半乳糖的酸乳微观稳定性较好。因此,3 种益生元对酸乳的凝胶过程及微观结构的影响各不相同,未来还可对3 种益生元进行复配处理,添加到酸乳中进一步探究对其综合品质的影响。     

Invited review: Probiotic yogurt quality criteria,regulatory framework,clinical evidence,and analytical aspects

Yogurt is a milk-based product manufactured by lactic acid fermentation enabled by symbiotic yogurt cultures. Yogurt is largely considered to be a health product, and it is employed to deliver probiotics and prebiotics to the consumer. However, not all yogurts are probiotic, neither are they all functional products. There is increasing demand for health-promoting beverages, which is prompting the dairy industry to develop functional probiotic yogurts to meet the demand. However, there seems to be a scarcity of reviews providing critical information on regulatory frameworks in regions of the world, clinical trial outcomes, and methodological approaches for enumerating multiprobiotic strains in yogurt. This review, relating to functional probiotic yogurt, covers the newest information on the topic for the period mostly between 2014 and 2019. Conformance to regulations is paramount and hence, global regulatory frameworks for probiotic yogurt and prebiotic and nonprebiotic ingredients included in yogurt are reviewed. The paper emphasizes the need for convincing clinical trial outcomes that provide the dairy industry with an opportunity to market products with substantiated beneficial claims. The paper also discusses probiotic strains in functional yogurt, which is required to have population levels above the recommended therapeutic minimum during shelf life. The multiprobiotic species added to yogurt may present challenges relating to methodological and analytical approaches needed to determine viability of each strain contained in such yogurt. Hence, the review also presents the pros and cons of the culture-dependent and culture-independent approaches for the enumeration of probiotic cells in yogurt. The review is arguably valuable to the dairy industry, functional food developers, related scientists, and researchers, as well as policy makers.     

Sensory attributes of low‐fat strawberry yoghurt as influenced by honey from different floral sources,sucrose and high‐fructose corn sweetener

Low‐fat strawberry yoghurts were prepared with each of five alternative sweeteners: sucrose, high‐fructose corn syrup and honey from three different floral sources. A ninety‐nine‐member consumer panel evaluated the yoghurts for flavour, aroma, sweetness and overall acceptance. Degree of liking was scored by the panellists on a nine‐point hedonic scale. Panellists preferred sucrose‐sweetened yoghurts over those sweetened with high‐fructose corn syrup and honey (P < 0.05). Among the honey‐sweetened yoghurts, sage honey was the most liked (P < 0.05), followed by alfalfa‐ and sourwood‐sweetened yoghurts.     

Relationships between acceptability and sensory attributes of peach nectars using internal preference mapping

Eight samples of peach nectars were profiled by a trained panel and assessed for overall liking by a consumer panel. Internal preference mapping was used to derive a multidimensional space of samples based only on acceptance data. The first three preference dimensions showed significant fit for 91.2% of the consumer population. According to the position of these consumers on the maps, four subgroups could be formed. The first dimension was mainly related to sweetness and off-flavour. The second dimension was related to acidity and texture attributes (body, viscosity, sliminess, mouth-coating) and the third dimension was defined by flavour intensity, peach flavour, and artificial and cooked flavours. Based on these results, the preference criteria of each consumer subgroups were established. Received: 27 September 1999     

Effect of ideal–relative sweetness on yogurt consumption

The objectives of this study were to determine how hedonically different sweetness levels in yogurt, determined by the ideal–relative rating method, affected taste test liking ratings and consumption in a naturalistic setting. Nineteen subjects attended a preliminary session, a taste test and three lunch tests. During the taste test, they rated yogurt with three levels of sweetness (high, optimum, and low) for six attributes. During each lunch test, they were offered a tray of nine food items, including yogurt at one of the three sweetness levels. Subjects liked the optimally sweet yogurt best in the taste test and consumed the most of it at lunch. Taste test liking ratings did not predict the amount of yogurt consumed during lunch. The lower-than-optimum sweetness level was more detrimental to taste test ratings than was the oversweetened yogurt whereas the higher-than-optimum sweetness level was more detrimental to consumption during lunch than was the undersweetened yogurt.     

Yogurt Thickness: Effects on Flavor Perception and Liking

Nine flavored stirred‐style yogurts (thick and thin textured, colored and uncolored, flavored as either cotton candy, lemon‐lime, or strawberry) were evaluated by 120 panelists aged 11 to 14 y to analyze the interactive effects of flavor, thickness, and color on thickness intensity, flavor intensity, and degree‐of‐liking. Yogurt flavor did not affect thickness intensity nor liking ratings. Yogurt thickness did not affect flavor intensity, but flavor liking was affected by both flavor and thickness. Strawberry yogurt was liked equally in both texture systems, but cotton candy and lemon‐lime yogurts were liked more in a thick textured yogurt than a thin yogurt. Colored yogurts were thicker and more flavorful than uncolored yogurts.     

益生菌制剂及其发酵性乳制品

综述了益生菌的概念和益生菌菌株的选择标准、国外益生菌产品的发展状况、益生菌作为新型酸奶发酵剂的使用情况，以及益生酸奶的生产与消费情况。     

Sucrose‐free chocolate sweetened with Stevia rebaudiana extract and containing different bulking agents – effects on physicochemical and sensory properties

Sucrose‐free milk chocolates sweetened with Stevia and containing different types of commercial inulin or polydextrose as bulking agents, were examined in relation to their physico‐chemical, rheological and sensory properties. Compared with chocolate sweetened with sucrose, noticeable differences in lightness (L* values) were observed for sucrose‐free chocolates and attributed to changes in surface roughness. Chocolate containing inulin with a higher degree of polymerisation (DP) had higher melting points, greater plastic viscosity and an increased flow behaviour index. The Herschel‐Bulkley mathematical model most closely fitted to the rheological data. Chocolate containing the highest DP inulin was found to be very similar to control in tested sensory attributes (appearance, firmness, smoothness, mouth feel, flavour/taste and overall acceptance) when assessed by a consumer panel. These data indicate that it is possible to manufacture sucrose‐free chocolate using high DP inulin without adversely affecting its important physico‐chemical properties and sensory acceptance.     

Review on potential non-dairy synbiotic beverages: a preliminary approach using legumes

In the past few years, certain functional foods have gained consumer acceptance like those containing synbiotics (a blend of both prebiotics and probiotics) in different food systems. Synbiotics enhance gut functionality and confer health benefits to humans. However, due to the limitations exerted by dairy-based matrices like lactose intolerance, milk allergies, limited shelf life and inclination towards veganism, consumer’s interest in non-dairy foods has increased. Among the non-dairy matrices, legumes (such as chickpeas, kidney beans, lupin) are the less explored areas with the majority focus on only soya beans. The present review gives brief information about the different research associating with various legume-based probiotics, prebiotics and synbiotic foods narrowing down specifically to beverages. The integration of such information will allow the researchers to explore product development using new prebiotic ingredients that have not been studied in much detail and hold an exceptional potential to be employed in the synbiotic food industry.     

Acceptance of sugar reduction in flavored yogurt

To investigate what level of sugar reduction is accepted in flavored yogurt, we conducted a hedonic test focusing on the degree of liking of the products and on optimal sweetness and aroma levels. For both flavorings (strawberry and coffee), consumers preferred yogurt containing 10% added sugar. However, yogurt containing 7% added sugar was also acceptable. On the just-about-right scale, yogurt containing 10% sugar was more often described as too sweet compared with yogurt containing 7% sugar. On the other hand, the sweetness and aroma intensity for yogurt containing 5% sugar was judged as too low. A second test was conducted to determine the effect of flavoring concentration on the acceptance of yogurt containing 7% sugar. Yogurts containing the highest concentrations of flavoring (11% strawberry, 0.75% coffee) were less appreciated. Additionally, the largest percentage of consumers perceived these yogurts as “not sweet enough.” These results indicate that consumers would accept flavored yogurts with 7% added sugar instead of 10%, but 5% sugar would be too low. Additionally, an increase in flavor concentration is undesirable for yogurt containing 7% added sugar.     

Prebiotics enhance magnesium absorption and inulin-based fibers exert chronic effects on calcium utilization in a postmenopausal rodent model

Abstract: Age‐related changes in calcium metabolism play a role in the development of osteoporosis. A 4‐wk feeding study was conducted in 5‐mo‐old ovariectomized (OVX) Sprague‐Dawley rats to assess the effect of various dietary fibers on mineral metabolism and bone health parameters. There were 6 treatment groups: sham‐Control, OVX‐Control, OVX rats receiving daily estradiol (E₂) injections, and OVX rats receiving an AIN‐93M diet supplement with either an inulin‐based fiber (Synergy1® or Fruitafit HD®) or a novel fiber (polydextrose) at 5% wt. of diet. Calcium and magnesium metabolic balances were performed after early (3 d) and late exposure (4 wk) to dietary treatments. Rats receiving polydextrose had significantly higher net calcium absorption efficiency and retention than all control groups and a trend (P≤ 0.10) for higher calcium absorption when compared to inulin‐based fibers after early exposure but the advantage did not persist over long‐term exposure. The inulin‐based fibers had positive chronic effects on calcium metabolism that were related to changes in the gut, that is, production of short chain fatty acids and higher cecal wall weights. All fibers improved magnesium absorption and retention in early and late metabolic balances; effects on magnesium metabolism were more pronounced than for calcium. Practical Application: Steady growth in US middle‐aged and elderly populations has led to higher incidences of several chronic diseases including osteoporosis, a bone disease that primarily affects postmenopausal women. Recent research suggests that certain dietary fibers (prebiotics) enhance mineral absorption and may impart bone health benefits. This work examines the impact of prebiotic supplementation on mineral metabolism and bone health using a postmenopausal rat model. Study findings will aid future investigations in ascertaining the factors related to potential bone health benefits of prebiotic which will aid in developing an effective prebiotics food product/supplement that will address the bone health needs of consumers.     

Potentially probiotic and synbiotic chocolate mousse

Several studies in recent years have shown the benefits deriving from the ingestion of probiotics, and a large number of products containing lactobacilli and bifidobacteria have been formulated. The purpose of this study was to develop a chocolate mousse to which probiotic and prebiotic ingredients were added, and verify the perspectives of the product with regard to potential for consumer health benefits and sensorial acceptance. Probiotic and synbiotic chocolate mousse supplemented with Lactobacillus paracasei subsp. paracasei LBC 82, solely (P) or together with the prebiotic ingredient inulin (S), were prepared, as well as a control mousse (C). The products were monitored for the population of L. paracasei and contaminants, during storage at 5 °C for up to 28 days, and sensory preference was also tested. Storage trials showed that the viability of the probiotic was retained over 28 days, but the growth of yeasts and moulds might limit the shelf-life of the product. Chocolate mousse was shown to be an excellent vehicle for the delivery of L. paracasei, and the prebiotic ingredient inulin did not interfere in its viability. Moreover, the addition of the probiotic microorganism and of the prebiotic ingredient did not interfere in the sensorial preference of the product.     

The Beneficial Use of Cereal and Cereal Components in Probiotic Foods

Cereals and cereal components can be used as fermentation substrates for probiotic organisms imparting prebiotic effects. Consumer interest in healthy functional foods has resulted in the need for food products with versatile health-benefiting properties. The conventional choice for probiotic food applications has been dairy-based products, but whole grain-based probiotic functional foods have debuted in Japan and Europe. In the US, pro- and prebiotics are mainly marketed as dietary supplements, but are moving towards inclusion in the diet as mainstream foods. Cereal constituents, such as wheat bran-based ingredients fermented with probiotics, would enhance consumer health with the benefits of probiotics, bran fiber, and healthful bioactive components.