Sensory Evaluation Center, College of Agricultural Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
J Dairy Sci. 2013 Aug;96(8):4938-44. doi: 10.3168/jds.2013-6715. Epub 2013 Jun 13.
Chocolate ice cream is commonly formulated with higher sugar levels than nonchocolate flavors to compensate for the inherent bitterness of cocoa. Bitterness, however, is an integral part of the complex flavor of chocolate. In light of the global obesity epidemic, many consumers and health professionals are concerned about the levels of added sugars in foods. Once a strategy for balancing undesirable bitterness and health concerns regarding added sugars has been developed, the task becomes determining whether that product will be acceptable to the consumer. Thus, the purpose of this research was to manipulate the bitterness of chocolate ice cream to examine how this influences consumer preferences. The main goal of this study was to estimate group rejection thresholds for bitterness in chocolate ice cream, and to see if solid chocolate preferences (dark vs. milk) generalized to ice cream. A food-safe bitter ingredient, sucrose octaacetate, was added to chocolate ice cream to alter bitterness without disturbing other the sensory qualities of the ice cream samples, including texture. Untrained chocolate ice cream consumers participated in a large-scale sensory test by indicating their preferences for blinded pairs of unspiked and spiked samples, where the spiked sample had increasing levels of the added bitterant. As anticipated, the group containing individuals who prefer milk chocolate had a much lower tolerance for bitterness in their chocolate ice cream compared with the group of individuals who prefer dark chocolate; indeed, the dark chocolate group tolerated almost twice as much added bitterant in the ice cream before indicating a significant preference for the unspiked (control) ice cream. This work demonstrates the successful application of the rejection threshold method to a complex dairy food. Estimating rejection thresholds could prove to be an effective tool for determining acceptable formulations or quality limits when considering attributes that become objectionable at high intensities.
巧克力冰淇淋通常比非巧克力口味含有更高的糖含量，以弥补可可的固有苦味。然而，苦味是巧克力复杂风味的一个组成部分。鉴于全球肥胖症的流行，许多消费者和健康专家都关注食品中添加糖的含量。一旦开发出平衡不良苦味和添加糖的健康问题的策略，任务就变成了确定该产品是否会被消费者接受。因此，本研究的目的是控制巧克力冰淇淋的苦味，以研究这如何影响消费者的偏好。本研究的主要目的是估计巧克力冰淇淋苦味的群体拒绝阈值，并观察巧克力的偏好（黑巧克力与牛奶巧克力）是否推广到冰淇淋。一种食品级苦味剂——八乙酸蔗糖酯，被添加到巧克力冰淇淋中，以改变苦味，而不会干扰冰淇淋样品的其他感官特性，包括质地。未接受过训练的巧克力冰淇淋消费者通过对未加味和加味的配对盲样进行偏好指示，参与了一项大规模的感官测试，其中加味样的苦味剂含量逐渐增加。正如预期的那样，与喜欢黑巧克力的人群相比，更喜欢牛奶巧克力的人群对巧克力冰淇淋的苦味容忍度要低得多；事实上，黑巧克力人群在表示对未加味（对照）冰淇淋有明显偏好之前，能够耐受冰淇淋中几乎两倍的添加苦味剂。这项工作证明了拒绝阈值方法在复杂乳制品中的成功应用。估计拒绝阈值可能成为确定可接受配方或质量限制的有效工具，特别是在考虑到在高强度下变得令人反感的属性时。
