Effect of saliva on physical food properties in fat texture perception

Sensory properties of food drive our food choices and it is generally accepted that lipids greatly contribute to the sensory properties of many foods and consequently to eating pleasure. Many studies have investigated the mechanisms of the fat perception. Unfortunately they used a variety of methods and products, thereby making generalization very difficult. The mechanism of fat perception in oral cavity is combined of several processes. Lipid composition and its properties strongly influence food structure. During consumption food is exposed to a range of in-mouth processing steps. Oral sensation of fat texture changes with time, from a first bite to chewing, while mixing with saliva, up to swallowing and even after swallowing. The present work reviews many aspects of fat texture perception from physical chemistry to physiology. Understanding the underlying mechanisms of in-mouth lipid processing would provide new concepts to produce low-fat food products with full-fat perception.     

Changes in texture, colour and fatty acid composition of male and female pig shoulder fat due to different dietary fat sources

Two experiments with 72 slaughter pigs in each were conducted. Entire males and females were individually fed restricted. Palm kernel-, soybean- and fish-oil were used in varying combinations, giving different dietary fat levels (29-80 g/kg) and iodine values ranging from 50 to 131. Shoulder fat was analysed for fatty acid composition (inner and outer layer), firmness and colour. A clear dose-response relationship was seen between fatty acids in diets and in shoulder fat. Interestingly, the very long chain n-3 fatty acids seemed to be deposited more efficiently when additional fat was included in the diet. Both high and low dietary iodine values changed towards less extreme iodine values in fat. Low-fat diets enhanced de novo synthesis of fatty acids. Males revealed a higher percentage of PUFA and a lower percentage of C18:1 and MUFA. Fat firmness, but not colour, was influenced by sex and dietary fat source.     

Understanding of the influence of composition,structure and texture on salty perception in model dairy products

The aim of this study was to better understand salt release and perception in model dairy products, having different composition, structure and/or texture. Sensory and instrumental methods were used to quantify and relate texture to salt mobility and perception. A high dry matter content (protein and fat jamming) and a gel structure with a protein network formation induced a decrease of diffusion coefficient of salt in matrices. Moreover, salty perception was higher for non-renneted products than for gelled ones. For gels, saltiness was enhanced in fat products. These results were discussed in regards with textural and physico-chemical food properties: the structural parameter tan δ was the most correlated with salty perception highlighting the impact of product structure on saltiness. Results also demonstrated that physiology and complex events (mastication, dilution and mixing with saliva, dynamic of bolus formation) occurring during food consumption must be considered to go further in understanding.     

Surface texture of foods: perception and characterization

Surface texture is generally accepted as a key sensory factor of food materials and has great impact on consumers' perception and expectation of a food product. However, no authentic definition has been given in the literature for the term surface texture. Its real meaning is often rather confusing, varying from case to case and from person to person. A general consensus is that surface texture is a multi-parameter sensory factor composed of those surface-related features which can be perceived by visual, tactile handfeel, and tactile mouthfeel senses. A list of such surface-related features has been produced in this review, and of those, topographical properties are probably the most intensively investigated features in literature and are discussed in detail in this paper. The surface texture of a food can be characterized by either sensory panel tests or by physical instrument tests. The former uses panellists (trained or untrained) for sensory assessment, while the latter applies physical techniques to characterize the surface. While sensory tests are widely used for studies on consumers' perception and preference of foods, instrumental characterization uses one or few parameters to define a surface (either qualitatively or quantitatively). Physical techniques used for surface characterization are categorized into two groups: surface contacting and non-surface contacting. The former include tribometer, surface force apparatus, contact profilometry, atomic force microscopy, friction force microscopy, etc. Non-surface contacting techniques include gloss metre, fiber optic reflectometer, angle-resolved light scattering apparatus, surface glistening points method, electron microscopy, confocal laser scanning microscopy, etc. The principles and application examples of these techniques were discussed in this review.     

Influence of proteins on the perception of flavored stirred yogurts

Among yogurt dairy components, protein type is known to modify the texture of the products and the volatility of odorous volatile organic compounds. The aim of this study was to investigate the impact of 3 protein ratios (caseinate to total protein) on the sensory properties of 4% fat, strawberry-flavored stirred yogurts. A sensory methodology study was therefore investigated to choose the most efficient method in terms of sensitivity, quantification, and ease with which the panel could distinguish slight differences in olfactory property between the yogurts. Three kinds of product presentation procedures were compared: a monadic presentation, a comparative presentation, and a comparative presentation with a reference. The results showed that the 3 presentation methods emphasized some important texture differences between the yogurts in the same way. However, the comparative procedure with a reference was the only one to reveal clear olfactory property differences between the yogurts. The main effect of protein ratio variation in yogurt concerned the texture properties, which greatly differed between the 3 yogurts and was confirmed by complex viscosity measurements. Olfactory differences between the yogurts were more subtle. Overall, the flavor intensity and the fruity notes were less intense in the yogurts with the high caseinate ratio than in those with the low ratio. This result was in agreement with the physicochemical measurements, which showed a higher retention of a large majority of aroma compounds of the strawberry flavor in the yogurts with a high caseinate ratio.     

斩拌速度和时间对乳化肠质构的影响

研究斩拌速度、时间与乳化型香肠质构之间的关系.采用响应曲面设计,选用斩拌速度和斩拌时间为试验因素,测定不同斩拌时间和速度下产品的硬度、弹性、内聚性、咀嚼性和回复性.结果表明,斩拌速度对乳化肠的硬度、弹性和回复性均有显著影响,斩拌时间对回复性有显著的影响,斩拌速度和斩拌时间的交互作用对硬度和回复性有显著的影响;斩拌速度为6 000 r/min,斩拌时间为9 min时,形成的乳化肠的硬度、弹性、内聚性、咀嚼性和回复性最佳,满足乳化肠质构的要求.     

Reducing salt and fat content: Impact of composition,texture and cognitive interactions on the perception of flavoured model cheeses

To better understand which composition levers are available to reduce salt content in food without altering flavour perception, this paper aimed at quantifying the impact of texture and composition (salt, fat and dry matter) of a model cheese: (i) on salt and flavour perception, and; (ii) on profile texture and flavour release.     

Modelling sweetness and texture perception in model emulsion systems

Model emulsion samples, prepared subject to a d-optimal response surface design, were used to investigate the effect of rapeseed oil, sugar and hydroxypropyl methyl cellulose thickener (HPMC) on perceived sweetness, textural attributes (thickness, stickiness, mouth-coating, dispersing), instrumental measures of apparent viscosity 50 s⁻¹ and Kokini oral shear stress. An increase in oil, sugar and HPMC resulted in an increase in perceived thickness, stickiness and mouth-coating, and a decrease in dispersion; sweetness was enhanced by the addition of both sugar and oil but suppressed by the addition of HPMC. Viscosity and Kokini oral shear stress were well correlated with oral thickness (r ² > 0.9). Validated multiple linear regression models highlighted several 2-factor interactions between ingredients. Model statistics indicated that the variation in data was well explained; the models were predictive and could be used to navigate the design space. Samples predicted to be iso-thick and iso-sweet could not be discriminated (P > 0.10) in a 3-alternative forced choice (3-AFC) test using 35 panellists.     

Astringency: mechanisms and perception

Astringency plays an important role in the sensory experience of many foods and beverages, ranging from wine to nuts. Given the recent trend toward fortifying consumables with astringent compounds and the evidence regarding the health benefits of some astringents, the mechanisms and perceptual characteristics of astringency warrant further discussion and investigation. This paper reviews the current state of the literature, including consideration of new methods for describing and measuring astringency, and provides an overview of research concerned with elucidating the physical, physiological, and psychological factors that underlie and mediate perception of this sensation.     

Freezing-thawing effects on the colour and texture of European catfish flesh

The freezing-thawing effect on the colour of raw fillets and on the texture of cooked fillets of European catfish ( Silurus glanis ) was studied. European catfish coming from two rearing conditions occurring in France were analysed by sensory and instrumental measurements. Fillets of European catfish became lighter, yellower and less bright after a freezing-thawing cycle. An increase in hardness and a decrease in resilience, disintegration and shear resistance were also highlighted after a freezing-thawing cycle. We could make the hypothesis that these variations of colour and texture were due either to mechanical damage or muscle protein denaturation. Fillets also became less juicy after a freezing-thawing cycle because of a loss of water-holding capacity.     

Invited review: Sensory and mechanical properties of cheese texture

Instrumental mechanical properties (instrumental tests that measure force and deformation over time) of cheese and cheese texture (sensory perception of cheese structure) are critical attributes. Accurate measurement of these properties requires both instrumental and sensory testing. Fundamental rheological and fracture tests provide accurate measurement of mechanical properties that can be described based on chemical and structural models. Sensory testing likewise covers a range of possible tests with selection of the specific test dependent of the specific goal desired. Establishing relationships between instrumental and sensory tests requires careful selection of tests and consideration and analysis of the results. A review of these tests and a critical analysis of establishing relationships between instrumental and sensory tests is presented.     

鸡肉火腿肠添加物对质构的影响

采用质构剖面分析法(texture profile analysis,TPA)及感官评定,探讨了脂肪、淀粉、焦磷酸钠和大豆分离蛋白对鸡肉火腿肠质构的影响。结果表明:当鸡肉火腿肠的配方为脂肪10%、淀粉4%、焦磷酸钠0.4%、大豆分离蛋白1.5%时,鸡肉火腿肠的质构特性较好,其硬度为1488.11g、弹性0.9、内聚性0.73、恢复性0.28。其中脂肪含量对火腿肠的硬度、内聚性和恢复性影响最大(R分别为335.49、0.033和0.32),而焦磷酸钠添加量对鸡肉火腿肠的弹性影响最大(R为0.046)。通过感官评定与机械测定之间的相关分析,发现机械硬度-感官硬度、机械恢复性-感官恢复性和机械硬度-感官总体接受性相关性极其显著。     

影响面条质构测定因素的研究

研究了面条静置时间、冷却浸泡水温度、冷却浸泡时间等因素对面条质构特性测定结果的影响。实验表明:这些因素对面条质构测定结果均有影响,在测定质构特性以及用质构特性表示面条品质时,不能忽略这些因素的影响。     

猪血血浆分离蛋白对灌肠类制品质构影响的研究

以猪肉为主要原料,以猪血血浆分离蛋白为主要添加剂,设计不同配方制成灌肠然后测定各组分对灌肠质构的影响.通过正交试验确定最佳配方为:肥瘦比例为3∶7,猪血血浆分离蛋白的用量为3%,复合磷酸盐用量为0.3%,亚硝酸钠的添加量为0.001%.     

辐照对Provolone干酪化学成分和质构的影响

采用不同剂量的60Co-γ射线对Provolone干酪进行辐照处理,研究了辐照杀菌的干酪在储藏期间化学成分与质构的变化。结果表明:(1)储藏期间,随着辐照剂量的增加,辐照干酪的Aw呈降低趋势,辐照吸收剂量越大,Aw下降的程度也越强;酸价、过氧化值和TBA值明显增加;(2)储藏期间,随着辐照剂量的增加,pH4.6 SN和12%TCA SN的质量分数都呈下降趋势;辐照干酪的TPA硬度、弹性和凝聚性都呈下降趋势;(3)根据电泳图可知,Provolone干酪随着辐照剂量的增加,酪蛋白的水解程度降低,在副κ-CN以下的小分子量的快速迁移肽含量有明显的减少,而β-CN和副κ-CN之间的大分子量的迁移肽减少不明显。     

超细南瓜粉的质构特性研究

超细南瓜粉是经气流粉碎工艺制成的超细粉体(粒径在10μm以下).本文采用仪器测定和感官检验两种方法对超细南瓜粉的质构进行全面评定.实验结果表明,超细南瓜粉以食品配料的形式加入面粉中,按照通常面粉的评价指标进行各项品质性能及感官性能比较,均有明显差异.本文的测试结果为生产实践提供了基础数据,该研究结果对其它的超细粉体的应用也具有参考价值,是食品超细粉体质构研究的初步探索.     

应用质地多面剖析法评定烧鸡的感官质量

研究了应用质地多面剖析法评定烧鸡感官质量的方法,通过应用该方法评定烧鸡的质地,说明该方法能评定出烧鸡的质量好坏,适合于烧鸡的感官质量评价。     

Correlating instrumental measurements of texture and flavour release with human perception

Attempts to correlate sensory perception with analytical measurement of the physical or chemical properties of a food are widespread in both industry and academia. Reasons for this are discussed, along with some of the techniques employed. The inter‐relationship between instrumental analysis and sensory evaluation in the development and quality control of food products is emphasized. Three examples are drawn from the field of flavour research, where a combination of instrumental and sensory techniques was used for different purposes. Instrumental measures may be used to predict sensory quality within a known design space, provided this has first been validated with appropriate sensory methodology. It is true, however, that a significant correlation between analytical and sensory data does not necessarily imply that a causal relationship exists between the two.