食品脆度的客观表征及其通用测量公式的研究

食品的脆度指标因构成因素复杂,虽有少量探索,目前为止尚没有形成比较一致的客观表征和测量方法。本研究以具有脆度属性要求的各种蔬菜水果类食品为对象,建立食品的感官脆度评价与仪器测定质构图中提取的各种参数的相关性。把所得的力、斜率、面积、面积/ 距离等参数与感官平均脆度值进行相关性分析,结果表明：斜率与感官脆度值具有最高的相关性,据此建立脆度指标的表征模型。以饼干类食品对该模型进行验证,表明该模型对蔬菜水果及饼干类食品有较好的应用前景。     

脆度的研究方法及其控制参数

消费者对脆性食品的兴趣极大 ,有关食品脆性的研究很多 ,文中综述了部分相关文献 ,尤其是关于脆性食品研究的方法、仪器和感官鉴定方法。讨论了食品结构、水合和组成成分等参数对脆性及其稳定性的影响。     

An application of the ultrasonic pulse echo technique to the measurement of crispness of biscuits

The possibility of developing an objective method of measuring the crispness of biscuits using the ultrasonic pulse echo technique was investigated. An encouraging relationship between the crispness (from sensory measurement) and the velocity of longitudinal sound was found. A similar, but less convincing relationship was found between crispness and ultra sonic attenuation.
The ultrasonic velocity shows a better correlation with crispness than does the ultrasonically derived Young's modulus.     

Sensory, Acoustical, and Force-Deformation Measurements of Potato Chip Crispness

The auditory (sound only) and oral (normal biting and chewing) crispness of five different potato chip products, each adjusted to two moisture contents, were measured. Instrumental acoustical and force-deformation measurements were made on these same samples and compared with the sensory crispness measurements. Oral crispness judgments appeared to be made on the basis of both auditory and oral tactile sensations, since auditory crispness was not highly correlated to oral crispness. A combination of acoustical and force-deformation measurements provided an excellent measure of oral chip crispness.     

A review: Crispness in dry foods and quality measurements based on acoustic-mechanical destructive techniques

Research during the past years has focused on crispness because of the great interest of consumers towards crispy foods. Currently crispness is measured with sensory, mechanical and morphological variables. Recently, the analysis of acoustic recordings with mechanical testing results appears to be an interesting technique of crisp foods. The first part of this article reviews briefly the definition and the determination of crispness by different test methods. The second part summarizes the results of studies conducted worldwide on the crispness which use destructive acoustic-mechanical methods.     

基于气相色谱-质谱联用与偏最小二乘-判别分析的啤酒爽口性评价

目的：建立一种偏最小二乘-判别分析（partial least squares-discrimination analysis,PLS-DA）评价啤酒爽口性的方法。方法：基于顶空固相微萃取（headspace solid-phase microextraction,HS-SPME）结合气相色谱-质谱（gas chromatography-mass spectrometry,GC-MS）联用检测啤酒中爽口性相关指标转化为数据矩阵,利用SIMCA-P软件进行PLS-DA。结果：不同爽口性的啤酒在得分图中能够明显区分。根据载荷图显示爽口性较差的样品集DA（1）中敏感特征变量为辛酸乙酯、癸酸乙酯及乙酸异戊酯等酯类化合物。选取50 个样本为校准集,建立PLS-DA模型,4 个爽口性不同的啤酒样本模型的回归相关系数分别为0.861、0.798、0.765、0.812,样品辨别率为92%。利用建立的PLS-DA模型对27 个未知样品进行预测,不同爽口性样品的预测均方根误差分别为0.183、0.321、0.523、0.323,准确识别率为74.07%。结论：HS-SPME-GC-MS结合PLS-DA法是一种简单、快速、有效评价啤酒爽口性的方法。     

基于穿刺法库尔勒香梨果肉脆度评价研究

本研究采用二阶微分法和峰值法对不同成熟度库尔勒香梨果肉的穿刺力-变形曲线锯齿度进行度量计算,结合不同成熟度香梨果肉组织显微组织观察,分析了锯齿度指数CI、平均穿刺力Fcr、结构破裂空间频率Nsr、结构破裂平均比力fsr和脆功Wc随香梨贮藏时间的变化规律,并分析了这5个锯齿度度量参数与香梨可溶性固形物含量及含水率的相关性,比较了对香梨果肉脆度变化的敏感度。研究结果表明,不同成熟度香梨果肉穿刺力-变形曲线锯齿度有明显差异,随着香梨脆度减小,锯齿度指数CI、平均穿刺力Fcr、结构破裂平均比力fsr、脆功Wc呈逐渐减小趋势,而结构破裂空间频率Nsr呈逐渐增大趋势,这5个锯齿度度量参数都与可溶固形物含量、含水率显著相关,但是峰值分析法的结构破裂平均比力fsr不仅与可溶性固形物含量及含水率的相关系数都很高,而且对香梨脆度敏感度值最高,最适宜作为评价香梨果肉脆度的指标。     

谷物早餐质构特性——脆性的研究

脆性是食品感官品质中很重要的一种质构特性，主要包括声学特性和力学特性。脆性可以用感官评定法、力学检测法和声学检测法测定。挤压机的进料水分含量、螺杆速度、挤压温度都影响谷物的脆性和保脆性。原料中的蛋白质、淀粉、脂肪以及添加剂也会影响谷物的脆性和保脆性。     

Sensory Crispness of Crispy Rolls: Effect of Formulation, Storage Conditions, and Water Distribution in the Crust

ABSTRACT:  Crispness is an important sensory quality parameter that strongly influences the acceptability of cellular solid foods such as the crust of many types of breads. Crispness of the bread crust depends particularly on its water content. In this study, the relationship between sensory crispness of crispy rolls and the average water content of the crust was studied for different bread formulations (control, amylase, glucose-oxidase, and protease) and storage conditions (40% and 80% RH). From the different formulations used, only protease treatment increased the crispness of the crust and its retention at both storage conditions. The positive effect of the protease treatment was due to a lower water content of the crust of these breads compared to the other formulations. The relationship between sensory attributes, formulation, and storage conditions was found to be dominated by the dependence on storage conditions. When combining data for low and high humidity storage it showed that crusts with equal water contents could exhibit different scores for crispness. The results led to the hypothesis that a gradient of water content exists within the crust. At high humidity, the crust will take up water from both crumb and environment and a relative smaller gradient of water will exist within the crust. At low humidity on the other hand, the crust will take up water from the crumb only, resulting in a larger gradient of water within the crust.     

Relationships of Chewing Sounds to Judgments of Food Crispness

The relationships between biting and chewing sounds and judgments of food crispness were examined in two studies. In the first, subjects used magnitude estimation to separately judge the loudness of chewing sounds and the crispness of a wide range of wet and dry crisp foods. Judgments of perceived crispness and loudness were highly correlated both when food samples were fractured by single bites and when further broken down by chewing. In the second study, biting and chewing sounds were blocked by a loud masking noise. Subjects had no difficulty determining crispness. Correlations between judgments obtained with and without an auditory block were high. It is proposed that vibrations produced by fracturing crisp foods may underlie the perception of crispness.     

Effect of Cooking on the Crispness of Cassava Chips

ABSTRACT: :
Technology for the production of edible cassava chips was studied, using pretreatments such as cooking and partial drying to improve chip crispness. Different cassava varieties and types of cooking, such as boiling water and steam, were also investigated. The effects of such treatments were evaluated on chip friability criteria by using the Texture Analyzer TA.XT2, as well as affective tests for sensorial measurement. A significant correlation (-0.90592; p ≤ 0.05) was found between friability and sensory acceptance of chips from the cassava variety "IAC Mantiqueira." The absence of correlation (-0.66069; p < 0.05) for the variety "IAC 576.70" was considered highly positive, since the chips were sensorially accepted despite their high friability values.     

微波冻干怀山药脆片干燥过程中脆性变化与数学模型的建立

为确定微波冻干怀山药脆片在干燥过程中的脆性变化规律,以怀山药为原料,利用微波真空冷冻干燥设备进行干燥,结合干燥特性分析、扫描电子显微镜观察、压汞仪测试及穿刺测试等方法,分析怀山药脆片在干燥过程中的干燥特性、孔隙结构和质构特性变化,建立微波冻干怀山药脆片干燥过程中的脆性数学模型,从而预测怀山药脆片干燥过程的品质变化。结果表明：怀山药微波真空冷冻干燥全过程分为升速阶段和降速阶段,恒速阶段不明显;随着干燥时间的延长,物料的水分质量分数越低,孔隙网络结构越紧密;微波功率密度越大,物料的干燥速率越快,水分质量分数越低,孔隙网络结构越紧密;怀山药脆性最佳模型为DoseResp模型：y＝A1＋（A2－A1）/（1＋10（（lg x0－x）p））,R2＞0.99,其中x为水分质量分数,y为脆性,A、x0、p为系数常数,该模型可较好地预测怀山药脆片的脆性变化规律。     

Water Sorption and Crispness of Fat-Free Apple Chips

ABSTRACT: Equilibration of fat-free apple chips to predetermined moisture level was achieved by keeping samples over saturated salt solutions. The sorption isotherm obtained indicated absence of a monolayer and was typical for type III according to the Brunauer classification. At water activity below 0.12 apple chips demonstrated excellent crispness and were highly acceptable as a snack food item. They were extremely hygroscopic and lost crispness easily. The critical water activity was found to be a_c= 0.18 which corresponds to a water content of 3.5 g H₂O/100 g solids. These values were much lower than those found for other crispy snack foods.     

Effect of Water Activity on the Sensory Crispness and Mechanical Deformation of Snack Food Products

Potato chips, popcorn, puffed corn curls, and saltines were equilibrated to various water activities (a_w) over saturated salt solutions. Sensory panels determined the crispness and textural hedonic quality of the humidified products by the magnitude estimation technique coupled to a verbal concept scale. Critical water activities (a_c), where the products became organoleptically unacceptable, generally fell in the 0.35–0.50 a_w range. Instron analyses showed that the force-deformation curve changed distinctly near the a_c for saltines and puffed corn curls, while the curve changed more gradually with increasing a_w for popcorn. Potato chips did not produce a consistently shaped force-deformation curve. The cohesiveness value of popcorn was found to be a good indicator of its sensory crispness.     

RELATIONSHIP BETWEEN WATER ACTIVITY AND CRISPNESS OF EXTRUDED RICE CRISPS

Extruded rice crisps were adjusted to water activities in the range of 0.05–0.65, and texture measurements were carried out by single compression or compression of a layer of 10 specimens. Sensory crispness ranking was performed by a panel familiar with texture evaluation. Several parameters were derived from the force/displacement curves, and a crispness indicator was calculated on the basis of the relationship between the texture parameters and water activity. This crispness indicator showed best correspondence sensory results, especially when layer compression was performed.     

Crispness level of potato chips affects temporal dynamics of flavor perception and mastication patterns in adults of different age groups

Little attention has been paid to the texture–flavor association in solid foods, especially crisp foods. This study aimed to determine whether crispness level affects temporal dynamics of perceived intensity of three types, i.e., plain, cheese, and spicy, of flavored potato chips with respect to three age groups: younger (20–25 years), middle-aged (40–45 years), and older (65+ years) adults. While eating potato chips, participants’ mastication pattern was also assessed by electromyography (EMG). Time–Intensity analysis showed that flavors were rated more intense and maximum flavor perception occurred quicker as crispness of potato chips increased. Overall, the effect of crispness level on flavor perception was more pronounced in the older participants. The average chew strength was greater in the crisper samples and regardless of flavor type the younger participants displayed shorter chew durations than older adults. A partial least squares regression demonstrated that mastication patterns, such as the number of chews, could well predict several key temporal flavor parameters such as the maximum intensity and the area under the curve in the middle age and older age groups. In conclusion, this study extends previous research showing that textural characteristics can influence flavor perception in liquid and soft foods to crisp/brittle foods. In addition, the effect of crispness level on flavor perception varies by flavor type, age group, and mastication pattern.     

Understanding potato chips crispy texture by simultaneous fracture and acoustic measurements, and sensory analysis

The fracture and acoustic properties of six commercial potato chips that differ in sensory hardness and sensory crispness were analysed and related in this work. Principal component analysis showed a correlation among the sensory attributes and the instrumental parameters (both mechanical and acoustic). Two components mainly explained the behaviour of the different potato chips. The first component was positively related to the number of force and sound events, to sound pressure level maximum, to the area under the force curve, and to sensory crispness, and negatively related to fat content; and the second component was positively related to the gradient (slope of the first part of the curve), the potato chip thickness, and to sensory hardness and sensory crispness. The behaviour of the different potato chips was explained by either one of the two components or by both components. Results indicate that certain degree of sensory hardness is necessary for higher crispness perception.     

大豆渣粉在酥性饼干中的应用研究

目的 研究大豆渣粉在酥性饼中的应用, 探究酥性饼干中大豆渣粉适宜添加量。方法 采用粉质仪和拉伸仪测定大豆渣粉对面团流变学特性的影响,采用质构仪测定面团和酥性饼干的物性参数,采用感官分析法评价大豆渣粉对酥性饼干感官品质的影响。结果 当大豆渣粉质量分数从0%增加到6%时, 面团稳定时间下降了50.99%,面团稳定时间小于3.5min,拉伸能量下降24.36%,感官评价酥性饼干的酥松度增加6.81%,质构仪测定酥性饼干的酥脆性增加35.14%,酥性饼干的感官评分变化不显著 (P>0.05)。当大豆渣粉质量分数为6%时, 大豆渣酥性饼干感官评分为66.03分, 与空白相比, 酥性饼干的感官评分下降幅度小于10% (P<0.05),酥性饼干的酥松度达到最大值。当大豆渣粉质量分数超过6%时, 酥性饼干的酥松度开始下降, 硬度显著增大 (P<0.05), 饼干的口感变差, 感官评分下降显著 (P<0.05)。结论 大豆渣粉在酥性饼干中的适宜添加量为6%时, 此时酥性饼干变得更加酥脆, 感官品质不仅合格, 而且提高了酥性饼干的营养价值。