RELATIONSHIP BETWEEN INSTRUMENTAL AND SENSORY ANALYSIS OF TEXTURE AND COLOR OF POTATO CHIPS

The instrumental and sensory analysis of the texture and color of commercial potato chips were compared. The instrumental measurement was a puncture test with an Intron Universal Testing Machine, and the parameters used were fracture force, deformation and stiffness. The instrumental color quantification was a computerized video image analysis technique, and the color was expressed as L*a*b* values. Sensory evaluation of texture and color was performed by a sensory panel especially trained in evaluating potato chips. The sensory attributes were "hardness", "chewiness", "crunchiness", and "tenderness" for texture analysis, and "yellow color", "burnt aspect", "sugar colored aspect" and "transparency" for color analysis. The factor analysis of the sensory attributes indicated that texture can be divided into two principal components, one represented by "hardness", "crunchiness" and "chewiness", and the other by "tenderness" alone. The factor analysis of the color can be divided into two principal components, one including "yellow color" and "burnt aspect", and the other "sugar colored aspect" and "transparency". Discriminant analysis showed that "tenderness" and "crunchiness" could predict correctly over 90% of the data. Fracture force correlated well with all of the sensory attributes (R² > 0.76), and L* with the sensory color attributes (R² > 0.79). The "Tenderness" was the individual sensory attribute which had the highest correlation (R²= 0.95) with fracture force.     

昌化鸡血石的宝石学研究

利用X射线粉末衍射仪、拉曼光谱仪、扫描电子显微镜、电子探针及岩石薄片对昌化鸡血石样品中"地"与"血"的矿物组成、形貌特征、化学成分等进行了研究.结果表明,昌化鸡血石"硬地""软地"与"冻地"的矿物组合不同;其中,"地"以地开石为主且呈鳞片状,随着石英的增加,特别是明矾石的加入,"地"的硬度变大."冻地"鸡血石中地开石的结晶粒度比"硬地"鸡血石中的大,但其空间定向性排列没有后者的好.昌化鸡血石中"血"由细小的半自形-他形辰砂微晶集合体组成,其"血"色与辰砂晶体的聚集状态及其杂质成分有关,而杂质成分又与Se元素的质量分数密切相关.     

三种仿寿山“坑头冻”印材的宝石矿物学特征

寿山水坑石十分稀罕且昂贵,"坑头冻"乃其典型品种。采用XRD,FTIR,ICP-MS,SEM等测试仪器对目前市场上出现的仿寿山"坑头冻"的"青海白""丹东白""岩门晶"三种印材的矿物组成、化学成分以及微观结构进行了研究,并与寿山"坑头冻"进行了对比分析。结果表明,"坑头冻"由地开石组成,具特征的"萝卜丝纹",质量分数中较高的Fe可能由黄铁矿包裹体所致;"青海白"主要矿物组成为石膏,硬度较低;"丹东白"主要矿物组成为斜绿泥石,其灰蒙蒙状外观由墨绿色斑点状杂质所致;"岩门晶"主要由地开石组成,具较高质量分数的V,Cr元素可能是其总带有浅黄绿色调的原因。SEM的观察结果发现,"坑头冻"晶体的结晶程度好,呈假六方片状结构;"青海白"的板状石膏晶体粒度大、厚度大,堆积不紧密,易与其它三者区分;"丹东白"中的斜绿泥石片晶薄且堆积紧密,挠性发育,手感滑快;"岩门晶"与"坑头冻"的特征较为相似,但前者的结晶程度稍低。"坑头冻""青海白""丹东白""岩门晶"在矿物组成、化学成分及显微结构上的差异以及在颜色、光泽、密度、包裹体等方面存在的不少差异,可作为四者的鉴别特征。     

“紫龙晶”与“绿龙晶”的宝石学特征

"紫龙晶"的宝石学名称为查罗石.目前,在珠宝市场上有一种与"紫龙晶"的结构较相似的宝石产品"绿龙晶",很多商家将其作为"紫龙晶"销售.为了验证"绿龙晶"与"紫龙晶"是否为同一宝石品种,对两种样品进行了常规宝石学测试、红外光谱以及X射线粉末衍射分析.结果表明,两者在颜色与硬度上有很大的差异,其结构、密度和折射率等基本相同;"紫龙晶"样品的主要矿物组成为查罗石,"绿龙晶"样品的则为绿泥石,两者并不属于同一种宝石.     

四个荔枝品种采后低温贮藏品质指标差异分析及评价

为了探讨(4±1)℃低温条件下贮藏对"妃子笑"、"桂味"、"糯米糍"、"淮枝"四个荔枝品种品质指标的影响,以色差值、褐变指数、好果率、可溶性固形物、可滴定酸、呼吸强度为指标进行研究,并采用主成分分析建立线性回归方程和评价模型,对四个品种进行综合评价。结果表明:随着贮藏时间的延长,四个荔枝品种色差值变化不同,"妃子笑"最稳定。褐变指数均呈递增趋势,"糯米糍"增加最明显,贮藏7 d,其褐变指数为4.267,好果率为0,"妃子笑"和"桂味"褐变程度低,贮藏14 d时,褐变指数分别为2.250和2.417,好果率仍高于60%。整个贮藏期间,"桂味"的可溶性固形物含量变化最大,下降7.19%,"淮枝"变化最小,含量升高0.34%。可滴定酸含量先升后降,贮藏14 d,"糯米糍"下降幅度最大,达32.14%,"淮枝"变化不明显,另外两个品种在贮藏第21 d时才明显下降,分别下降38.78%和35.37%。在14~28 d内,"糯米糍"的果实呼吸强度明显高于其他三个品种,其呼吸作用旺盛。主成分分析综合得分不同,得分从大到小依次是"妃子笑" > "桂味" > "糯米糍" > "淮枝"。因此,在低温下,"妃子笑"和"桂味"更耐贮藏,品质指标更好;"糯米糍"和"淮枝"不耐贮藏,品质指标更差。     

Hunting science: Current position and classification of the discipline

Summary The author critically discussed the various concepts of emotion in science and the diverging interpretations of the term game. The global system of hunting science is presented as an organisation design based on the definition of hunting. Hunting is characterised as a type of relationship between man and animal. The hunter and the hunted animal are linked by hunting as a technical process. The discipline of hunting science is subdivided into three main categories: hunting culture, hunting zoology, and hunting operations. The entire knowledge covered by hunting science is further subdivided into several subjects subordinate to each of these categories.     

Involvement of Anthocyanins and other Phenolic Compounds in Radical-Scavenging Activity of Purple-Fleshed Sweet Potato Cultivars

ABSTRACT: The 80% ethanol extracts of 5 purple-fleshed sweet potato cultivars were separated into 2 fractions, anthocyanins- and phenolic compounds-rich fractions, to clarify the contribution of these constituents to the radical-scavenging activity. The separation was accomplished with an ethyl acetate liquid/liquid extraction. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity in each fraction and the contributors varied according to the cultivars. The dominant DPPH radical-scavengers in "Ayamurasaki" and "Kyushu-132" were anthocyanins rather than phenolic compounds, while those in "Miyanou-36" and "Bise" were phenolic compounds, such as chlorogenic acid. Furthermore, the high-performance liquid chromatography analysis of anthocyanins showed that "Ayamurasaki" and "Kyushu-132" were rich in anthocyanins with peonidin aglycon, whereas "Miyanou-36,""Bise," and "Tanegashimamurasaki" contained cyanidin aglycon.     

EFFECTS OF VARIOUS INGREDIENTS ON THE TEXTURE OF MILK JELLY

Effects of various ingredients on the texture of milk jellies prepared from gellan gum, milk powder, sweetener were examined using a sensory test and physical measuring apparatus. The data were analyzed by use of the modification ofScheffé's mixture experiment method in rectangular experimental area in the Scheffé's triangle. "Hardness" and "smoothness" of milk jellies estimated by a subjective method were influenced by the content of gellan gum. The evaluations of "milk flavor" and "sweetness" estimated by a subjective method were varied with the content of sweetener and evaluated as higher for softer milk jellies. The correlation coefficients between "hardness" estimated by a subjective method and "smoothness", "milk flavor", and "sweetness" estimated by a subjective method were negative.     

静电纺丝的模式

针对现阶段存在的静电纺丝模式进行了归纳与分析,其中常规纺丝模式包括 “点-板”、“线-板”、“板-板”静电纺丝;高效纺丝模式包括“多喷头”、“无喷头”静电纺丝;特殊纺丝模式包括“同轴”、“近电场”、 “离心”静电纺丝。对各模式的纺丝特点、技术优缺点、适用性等技术进展情况进行了总结,可为静电纺丝新模式的发展提供参考。     

Improving food safety within the dairy chain: an application of conjoint analysis

This study determined the relative importance of attributes of food safety improvement in the production chain of fluid pasteurized milk. The chain was divided into 4 blocks: "feed" (compound feed production and its transport), "farm" (dairy farm), "dairy processing" (transport and processing of raw milk, delivery of pasteurized milk), and "consumer" (retailer/catering establishment and pasteurized milk consumption). The concept of food safety improvement focused on 2 main groups of hazards: chemical (antibiotics and dioxin) and microbiological (Salmonella, Escherichia coli, Mycobacterium paratuberculosis, and Staphylococcus aureus). Adaptive conjoint analysis was used to investigate food safety experts' perceptions of the attributes' importance. Preference data from individual experts (n = 24) on 101 attributes along the chain were collected in a computer-interactive mode. Experts perceived the attributes from the "feed" and "farm" blocks as being more vital for controlling the chemical hazards; whereas the attributes from the "farm" and "dairy processing" were considered more vital for controlling the microbiological hazards. For the chemical hazards, "identification of treated cows" and "quality assurance system of compound feed manufacturers" were considered the most important attributes. For the microbiological hazards, these were "manure supply source" and "action in salmonellosis and M. paratuberculosis cases". The rather high importance of attributes relating to quality assurance and traceability systems of the chain participants indicates that participants look for food safety assurance from the preceding participants. This information has substantial decision-making implications for private businesses along the chain and for the government regarding the food safety improvement of fluid pasteurized milk.