INFLUENCE OF CHEWING AND SWALLOWING BEHAVIOR ON VOLATILE RELEASE IN TWO CONFECTIONERY SYSTEMS

Electromyography, electroglottography and turbine airflow technology were used to characterize the chewing, swallowing and breath flow profiles of 35 subjects during the consumption of two different (a gum Arabic‐ and carrageenan‐based) confectionery chews. Simultaneous volatile release measurements were obtained using atmospheric pressure chemical ionization mass spectrometry. Subgroups of subjects displaying different eating characteristics were identified for both products. Parameters accounting for the maximum variance (product 1, 42% and product 2, 52%) between the subgroups were chewing force, chewing rate, proportion of work and total number of chews. Volatile release measurements were significantly different between the subgroups from product 1. The impact of the different eating characteristics on volatile release from product 2 was less defined, and postulated to be a result of the contrasting textural properties. Manipulating in vivo breakdown of chewy confectionery products, by texture modification, may influence consumer's volatile release and subsequent flavor perception.     

INFLUENCE OF CHEWING EFFICIENCY ON TEXTURE AND FLAVOUR PERCEPTIONS OF FOOD

This study examined the effect of differences in chewing efficiency on selected panellists' perceptions of the stickiness and flavour of cooked pasta. Chewing efficiency was measured by the degree of breakdown of an almond, and weight loss of chewing gum after predetermined numbers of chews. Pasta was cooked for various lengths of time in tomato juice to provide a series of samples varying in texture and flavour. The attributes considered in this study were clearly understood and detected in all of the samples by all the subjects. Nevertheless the subjects differed in the time intensity representations of their perceptions of these attributes. Differences in the efficiencies with which subjects break down food in the mouth may account for the abilities of subjects to distinguish between samples in terms of texture and flavour.     

FOOD TEXTURE AND ITS EFFECT ON INGESTION, MASTICATION AND SWALLOWING

The oral processing of most semisolid and solid foods can be summarized in terms of two opposing mechanical influences: forces that fracture food particles versus those that make them adhere to each other. During either the ingestion of food into the mouth or the early stages of mastication, the aim of processing solid food particles is usually to fracture them. However, later on towards swallowing, adhesion is desirable in order to try to form a sticky food bolus that could clear the mouth of isolated food fragments. Neither of these tendencies is actually a function of any particular force (or stress) or displacement (or strain) on food particles, but is instead controlled by energy. Food particles can adhere not only to each other but to the mouth's surfaces. This produces friction. While this is essential for the tongue to grip food particles and move them around the mouth, it also adds to the work that mouthparts must do during processing and may affect sensory perception of food quality. Successful processing of foods in the mouth requires a considerable amount of neural feedback from sensory receptors. We focus here on recent evidence about these sensory receptors with an attempt to reinterpret their role in terms of textural perception.     

CHEWING PATTERNS OF VARIOUS TEXTURE FOODS STUDIED BY ELECTROMYOGRAPHY IN YOUNG AND ELDERLY POPULATIONS

The effects of food texture on the chewing patterns of elderly and young people, masticatory recordings using electromyography (EMG) were carried out. Fourteen French adults (mean 29.4 years) and 23 elderly (mean 67.7 years) participated. Six food products (rice, beef, cheese, crispy bread, apple and peanuts) were tested. The chewing pattern of elderly subjects was characterized by a significant increase of number of chews and chewing duration for all foods except rice. Whatever the food type, muscle activity per chew (mean amplitude × burst duration) was lower for elderly than for young subjects. Single chews appeared less effective for food reduction in elderly than in young subjects. This can be partly compensated for by increasing the chewing duration and number of chews. No significant difference was found between both groups of subject for the total amount of EMG activity required prior to swallow whatever the food chewed.     

昆虫功能食品研究与发展探讨

昆虫是一类重要的生物资源，营养价值高，富含许多功能因子。在分析研究昆虫功能因子的基础上，对昆虫功能食品的开发作了较全面的综述，指出了昆虫功能食品开发存在的问题和应采取的对策，最后对昆虫功能食品的开发前景作了展望。     

COMPARISON OF PHYSICAL PROPERTIES OF AGAR, LOW GEL STRENGTH AGAR AND GELATIN, AS SUPPLEMENTARY FOOD FOR PEOPLE WITH SWALLOWING DIFFICULTY

Low gel strength agar (LGSA), recently developed as a supplementary food for swallowing was compared with ordinary agar and gelatin. LGSA was developed to have physical properties close to that of gelatin, while keeping one property of agar, i. e. its setting temperature which can be controlled comparatively easier than gelatin. Each specimen was prepared with and without orange flavor. After determination of their basic properties, i. e. hardness, adhesiveness, cohesiveness and gumminess, three samples of two flavors, six in all, were studied for ease of swallowing using electromyography and sensory evaluation, on middle age (40 to 60 years old) and senior age (60 to 70 years old) subjects. Those experiments revealed nearly the same results with all samples, except for a slight difference in gumminess in LGSA and gelatin. No significant difference in electromyograms were noted in six samples or with age of subjects. It is feasible to employ agar materials together with gelatin in institutions whose members have swallowing disorders.     

STUDY ON FOOD PROCESS MONITORING BY SOLENOID SENSOR

ABSTRACT

Electric impedance spectroscopy (EIS) is able to find the material properties of organic materials, such as phase change, ion concentration, water transfer and water content. The relationships between important process properties of foods and their impedance to 1V‐AC input from 100 kHz to 5 MHz were determined experimentally by the use of an EIS system with two noncontact sensors (solenoids winded by ?0.5‐mm nichrome wire on polyvinyl chloride tubes; one is 86.3‐mm length, the other is 247‐mm length). The model foods, which were aqueous glucose solution (0–50%) and sucrose solution (0–50%), showed a negative linear function between the concentration and the inductance obtained from the impedance values. However, sodium chloride solution (0–40%) presented a form of an exponential function. For agar gel (2–10%), the relationship between the hardness and the inductance was a positive linear function, which means that the inductance increases with the increase of gel hardness. These relationships were confirmed in yogurt processing. The system can be applied to yogurt processing as a technique for monitoring both fermentation and coagulation. In pudding processing, through this system, it can be found that the change of temperature affected the efficacy of the used system.

PRACTICAL APPLICATIONS

In this work, an electric impedance spectroscopy (EIS) system with a noncontact sensor was used to monitor some food processing, for example, to monitor the fermentation and coagulation processing of producing yogurt. The results show that the EIS system with a noncontact sensor has the feasibility to be applied to monitoring food processing or nondestructive testing.

     

芒果落果、疏果加工开胃食品的工艺研究

探讨了选用芒果落果、疏果为原料，加工芒果腌菜、酸辣芒果片和话芒果的工艺技术，认为利用芒果落果和疏果加工制作开胃食品具有原料廉价、质地佳、风味突出、工艺简单等特点，便于在芒果产区普及推广。     

NUMERICAL MODELING AND SIMULATION ON THE SWALLOWING OF JELLY

Studies of the swallowing process are especially important for the development of care foods for dysphagia. However, the effectiveness of experiments on human subjects is somewhat limited due to instrument resolution, stress to the subjects and the risk of aspiration. These problems may be resolved if numerical simulation of swallowing can be used as an alternative investigative tool. On this basis, a numerical model is proposed to simulate the swallowing of a simple jelly bolus. The structure of the pharynx was modeled using a finite element method, and the swallowing movements were defined by pharynx posterior wall shift, laryngeal elevation and epiglottis retroflexion. The rheological characteristics of the jelly were investigated using an oscillatory rheometer and a compression test. A Maxwell three-element model was applied to the rheological model of the jelly. The model constants were obtained from compression tests because the mode of deformation and the stress level of the compression tests were similar to those of the swallowed jelly. The frictional relationship between the organs and the jelly was estimated experimentally from some frictional measurements between the jelly and a wet sloping surface. The results of the simulations for the soft and hard jellies showed different patterns of swallowing that depended on their hardness, and the soft jelly produced faster swallowing because of its flexibility.

PRACTICAL APPLICATIONS

The object of this study is to develop a numerical simulation model of swallowing. Numerical modeling is suitable for the quantitative analysis of the swallowing process and may also be expected to enable a systematic study of care foods that are safe and offer some degree of comfort to patients suffering from swallowing disorders. The computer simulation can be used for evaluation without dangerous risks to the patient.     

固相萃取HPLC法同时测定食品中乙基麦芽酚和香兰素

建立了食品中乙基麦芽酚和香兰素的高效液相色谱测定法。方法采用C18（5μm，4．6mm×250mm i．d）反相色谱柱，流动相为乙腈和0．02mol/L磷酸二氢钠溶液，流速1．0mL/min，检测波长276nm，柱温30℃，进样量20μL。该方法的检出限0．5μg/g-2．0μg/g，测定低限饮料1mg/L,-4mg/L，固态食品为5μg/g-20μg/g，线性范围2．0mg／L～100mg/L，加标回收率97．1％～88．7％，相对标准偏差为4．27％～6．74％（n=9）。     

ACYLATION OF FOOD PROTEINS AND HYDROLYSIS BY DIGESTIVE ENZYMES: A REVIEW

The acylation of proteins involves the covalent attachment of acyl groups such as fatty acids and amino acids to both α- and ε-amino groups of the polypeptide chain. Chemical methods are currently used to covalently attach amino acids to casein via isopeptide bonds. By modifying food proteins with acylation, it is possible to increase the nutritional value of the protein, judging from growth tests on rats. Enzymatic methods via transglutaminase and human placental factor XIII for preparing protein derivatives have also been tested. In vitro hydrolysis studies using intestinal homogenates have indicated that the intestinal mucosal hydrolases efficiently cleave acylated proteins as well as ε-peptide bonds. Hog intestinal aminopeptidase N, as well as N-acylpeptide hydrolase and acylase I have been found to be responsible for the biological utilization of N-acylated food proteins.