Understanding the texture of low moisture cereal products: mechanical and sensory measurements of crispness

The texture of extruded starch products has been measured sensorially and instrumentally. The instrumental data were analyzed using different approaches such as fractal analysis and peak analysis. The data showed useful correlations between sensory crispness and crackliness and a parameter obtained from the application of a newly developed fractal method to analyze the force deformation curve obtained from a penetration test of the cereal samples. This suggests that fractal analysis of the force‐deformation plots could be used instead of sensory analysis. Moreover, it was observed that an increase in water content altered the texture of starch based samples from crispy to crackly, whereas the texture of starch‐sucrose samples remained unchanged in the same hydration range. © 2000 Society of Chemical Industry     

Methodological developments in crispness assessment: Effects of cooking method on the crispness of crusted foods

A new method was developed to assess the texture of crispy-crusted foods with a soft, high-moisture core. This method, applied to commercial pre-cooked chicken nuggets, combines characteristics derived from the force/displacement curves of the whole sample with characteristics of the simultaneously emitted sound. The use of a not-sharp blade probe to perform the test proved to be an effective technique for characterizing the texture of chicken nuggets after different final cooking processes. The force curves of the samples differed with the cooking process. Deep-fried samples and those cooked in a conventional oven presented jagged force curves and acoustic signals with many peaks, both characteristics of crispy products. The curve profiles of microwaved samples were drastically different and typical of tough, gummy products. The use of a susceptor package in microwave heating improved the crispness of the samples. The number of sound peaks was the acoustic parameter that best discriminated between the samples. It was found that although the moisture and fat contents of the core and crust are closely related to the texture characteristics, samples with similar water contents can have very dissimilar crispness characteristics. The fat content of the core did not change significantly with the final cooking process in any of the samples.     

New contact acoustic emission detector for texture evaluation of apples

A new contact acoustic emission detector (CAED) was developed for the instrumental texture evaluation of apples. The goal of this work was to determine the relations between instrumental parameters and sensory texture attributes, and to develop calibration models for prediction of the sensory texture of apples with CAED. Seven apple cultivars were used for the construction and validation of the models. CAED is particularly useful for evaluation of sensory crispness, crunchiness and hardness. There is also a significant correlation of acoustic emission counts with juiciness, mealiness and overall texture. Validation of the models indicates better prediction of these sensory attributes by total acoustic emission counts than prediction by puncture firmness in terms of variance explained, root-mean-square of a model prediction, and bias.     

质构分析在肉制品检测中的应用

质地特性是衡量肉与肉制品食用品质的重要参数,对肉品加工、贮运及安全都具有重要意义。质构仪是一种客观、快速衡量食品质地特性的方法,此方法已在肉制品、米面制品、乳制品、糖果、果蔬等食品的物性学分析得到应用。本文介绍了质构仪检测的原理和方法,综述了目前国内外质构仪在肉与肉制品品质检测中的应用情况,包括仪器质地参数与感官质地参数之间的相关性、肉制品品质与鲜肉新鲜度的检测、加工和食用品质的判别,肉制品生产工艺的优化等的国内外研究现状。     

Feasibility of the Acoustic/EMG System for the Analysis of Instrumental Food Texture

Acoustic/EMG system is presented to better measure the human perception of food texture through the use of sensory systems that monitor the mastication process. The sound transducer and EMG electrode system provide the means by which to measure the oral tactile sensation experienced by both masseter muscles and the auditory signals produced during mastication. Human testing was successfully preformed and signal data was recorded from both the EMG and acoustic sensors. The auditory signals, experienced by the subject during mastication, were recorded by a microphone placed in the ear. Maximum signal, total accumulative power and slope of accumulative power were extracted from the data and strong trends were seen, which corresponded to expected food texture within food groups. These parameters were able to distinguish between all products and similar trends were seen between EMG and acoustic results. The use of an acoustic sensor has the potential to drastically reduce commercial design costs and simplify data interpretation.     

INFLUENCE OF WATER ON THE CRISPNESS OF CEREAL-BASED FOODS: ACOUSTIC, MECHANICAL, AND SENSORY STUDIES

The texture properties of crispy breads were studied as a function of water content using compression tests, acoustic measurements and sensory analysis. The addition of water slowly lowers the characteristics associated with crispness up to 9%, after which they steeply decrease. Dynamic Mechanical Thermal Analysis (DMTA) measurements were carried out, at room temperature and at 5 Hz, on the same bread samples. The evolution of the textural properties of crispy bread are accompanied by an increase of the loss factor prior to the one associated to the glass transition. It was therefore proposed that the effect of water on the brittle character, on crispness and on the intensity of the sound emitted at fracture were due to the onset of molecular motions preceding or accompanying the glass transition.     

Relative importance of texture properties in the sensory quality and acceptance of commercial crispy products

BACKGROUND: Understanding the textural properties of a food can be important for producers and marketers of crispy products. Relationships between texture, overall sensory quality (OSQ) and consumer acceptance of different products have been a field of interest for many authors. Despite this, results of research concerning the importance of texture remain inconclusive. The aim of this study was to evaluate the relationship between texture and other sensory attributes on an example of potato chips and their OSQ and consumer acceptance. To determine which attributes played a dominant role in the OSQ of chips, statistical correlations were calculated. RESULTS: Among the 11 attributes analysed, three had a positive relationship with the OSQ. These were: fried potato odour (r = 0.487), fried potato flavour (r = 0.597) and crispness (r = 0.570). The negative relation was observed for off‐flavour notes (r = ? 0.740; ? 0.693). Among the texture attributes, also negative, but without a dominant influence on OSQ, were hardness and undesirable type of fragmentation. CONCLUSION: Texture properties were found to be significantly correlated with OSQ as well as with consumer acceptance, but other attributes, especially those with negative sensory effects, determined OSQ of the products examined and are of crucial importance for consumer acceptance. Copyright © 2008 Society of Chemical Industry     

Estimation of crispness and consumer acceptance of fried potato chips by mechanical and acoustic measurements

Fried potato chips retaining various moisture contents (MCs) (2.21–9.20%) were analysed to estimate the intensity of crispness and consumer acceptance by texture and acoustic measurements. The MC of the chips was highly correlated with the mechanical maximum force (MMF) in the texture measurement, total area (MTA) and number of sound peaks (NSP) in the acoustic measurement. The intensities of crispness and consumer acceptance decreased as the MC of potato chips increased. For the predictive models established, the combined use of mechanical and acoustic parameters was shown to better predict sensory crispness intensity [R² = 0.975, root mean square error of prediction (RMSEP) = 0.138] and consumer overall liking (R² = 0.966, RMSEP = 0.111) than either parameter alone. Based on the instrumental‐sensory crispness equivalent table established, the estimated values of the MTA were below 71.24, while the NSP should be above 22.81 to meet ‘slightly like’ category of consumer acceptance.     

面条的质构与感官评价的相关性研究

用质构仪分别测定市售的不同宽度、不同添加物的挂面和不同价位的油炸型方便面的质构参数,分析质构参数与面条感官评分之间的相关关系。结果表明:对于不同宽度的挂面,折断压力有助于客观评价面条的感官评价总分、适口性、韧性、光滑性;对于不同添加物的挂面,拉伸距离有助于客观评价面条的感官评价总分、色泽、表观状态;对于不同价位的油炸型方便面,最大剪切力、切割时间有助于客观评价面条的表观状态、韧性。另外,感官评价和仪器所定义的参数有一定的差别。     

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。     

火腿肠质地评价研究进展

在阐述食品质地概念的基础上,介绍肉制品的感官评价和仪器测定两种质地评价方法,重点阐述火腿肠质地评价的研究现状和存在的问题,展望仪器测定在火腿肠质地评价中应用前景.     

质构仪及其在食品品质检测方面的应用

质地特性是食品特别重要的品质因素,物性质构仪能够较好的反映出食品的这一重要品质因素,已经开始应用于各种食品的品质检测中。通过介绍质构仪的构造及工作原理,介绍其在面制品、肉制品、奶制品和果蔬等不同样品测试时探头的使用,参数的设定以及其他测试条件的设置,给科研工作者提供一定的参考依据。     

On the mechanism by which oil uptake decreases crispy/crunchy behaviour of fried products

A large problem for fried snack products with a crispy crust and a soft moist interior is that the crust often loses its crispy character fast, in the order of 3–20 min. As known during cooling of these snacks adherent oil will be sucked into the crust. The presence of oil in a cellular solid crispy material was found to affect the sound emitted on fracture dramatically, while it did not affect mechanical characteristics at least for shorter ageing times. Both the number of sound events and the acoustic energy released during fracture decreased. This could be explained by reflection of emitted sound at the oil–air interface. Both the smaller number of acoustic events and the lower loudness will cause a decrease in crispy perception of the crust and in that way oil uptake during cooling of fried snacks can explain their fast decrease in crispness after frying.     

On the assessment of fracture in brittle foods II. Biting or chewing?

In this study crispness assessment in different dry-crisp foods were evaluated. Roasted almonds with different degrees of roasting and two different types of extruded snacks, wheat crusts and cheese balls, at different water activities were used as samples. Crispness behaviour was characterised by using coupled sound–texture measurements and by sensory evaluation with the use of a consumer panel. Instrumental texture measurements were made using compression and penetration tests. While in the almond samples the compression test discriminated better than the penetration test among the samples, in both kinds of snacks the compression with the tooth-like probe proved to be as good as penetration tests to assess crispy characteristics. Consumers evaluated the samples by chewing with the back molars or by biting with the incisive teeth. The results obtained in sensory evaluation were similar to instrumental results. Consumers were able to better discriminate between the almond samples by chewing than by biting but in the snacks samples the ratings both by biting and chewing modalities were very similar and showing the same discrimination level. These findings could have useful applications: for panel training, at the time of naming attributes and defining how they are evaluated; also, to obtain the most of sensory-consumer correlations, having in mind that the “ease of breakdown” in the mouth is proved to contribute to the relative preferences among narrow texture ranges within products.     

HPMC and inulin as fat replacers in biscuits: Sensory and instrumental evaluation

Because a high fat content in foods is associated with health disorders, consumers demand low fat products, but without any loss of their texture quality. The instrumental texture and sensory properties of biscuits in which 15 and 30 g/100 g of the fat has been replaced by two different carbohydrate-based fat replacers (inulin and hydroxypropyl methylcellulose) were studied. The instrumental texture measurements showed that inulin and hydroxypropyl methylcellulose (HPMC) biscuits were harder and the sound emissions were higher than for the control biscuits. The trained sensory panel rated the biscuit with 15 percent fat replacement by inulin as crisper than the control. The consumer study revealed that fat replacement up to 15 g/100 g with inulin or HPMC provided acceptable biscuits, but higher replacement decreased the overall acceptability.     

食品的质构特性与新产品开发

介绍了在新产品开发中食品质构的构建，以厦开发过程中食品质构的感官评判和仪器分析，并讨论了感官评判结果与仪器分析数据的相关性。食品的质构特性是食品新产品开发中不可忽视的属性，值得研究开发者引起足够的重视。     

空心面品质评价方法的研究

以实验室制作的5种手工空心面为研究对象,用质构仪和色差仪分别测定面条的质构指标和色泽指标分析了空心面质构指标、色泽指标与感官指标之间的相关关系,建立了质构、色泽指标与感官指标的逐步回归模型。结果表明:质构仪的9个测量指标最大剪切力、韧性、硬度、黏附性、内聚性、胶着性、咀嚼性、回复性以及色差仪的3个测量指标亮度参数L*、红绿参数A*、黄蓝参数B*与感官评价所有6个单项指标以及总分都存在着极显著的相关关系。逐步回归分析发现,可以仅使用黏附性、内聚性、亮度L*和黄蓝参数B*这2个仪器测量值来代替感官评价总分。