Linking oral processing behavior to bolus properties and dynamic sensory perception of processed cheeses with bell pepper pieces

The addition of food particles to food matrices is a convenient approach that allows to steer oral behavior, sensory perception and satiation. The aim of this study was to determine the influence of physical-chemical properties of heterogenous foods on oral processing behavior, bolus properties and dynamic sensory perception. Bell pepper gel pieces varying in fracture stress and concentration were added to processed cream cheese matrices differing in texture. Addition of bell pepper gel pieces to processed cheeses increased consumption time, decreased eating rate and led to harder and less adhesive bolus with more saliva incorporated. Addition of bell pepper gel pieces to processed cheeses decreased dominance rate and duration of creaminess, smoothness, melting and dairy flavor and increased graininess and bell pepper flavor. Increasing fracture stress of bell pepper gel pieces from 100 to 300 kPa resulted in longer consumption time and lower eating rate. For hard/non-adhesive processed cheese matrices increasing gel pieces fracture stress lead to a boli with larger particles and more saliva. These changes were accompanied by decreased dominance perception of creaminess and bell pepper flavor and increased dominance of graininess. Increasing the concentration of bell pepper gel pieces from 15 to 30% did not affect oral behavior but led to the formation of harder and less adhesive bolus with larger particles and less saliva that were perceived with reduced dominance of creaminess, meltiness and dairy flavor while dominance of graininess and bell pepper flavor increased. Changing the texture of the cheese matrix from soft/adhesive to hard/non-adhesive decreased consumption time, increased eating rate, did not influence bolus properties and decreased dominance rate of creaminess, smoothness and melting sensations. Number of chews and total consumption time were positively correlated with saliva content of the bolus, number of bolus particles, bolus hardness, dominance of firmness, chewiness and graininess. We conclude that the modification of physical-chemical properties of processed cheeses and embedded bell pepper gel pieces can be a strategy to steer oral behavior and bolus properties which consequently determine dynamic sensory perception.     

Differences in habitual eating speed lead to small differences in dynamic sensory perception of composite foods

Previous studies demonstrated that variability in oral processing behaviors impacts bolus properties and consequently texture and flavor perception. However, most studies followed a prescribed mastication protocol during the products’ sensory evaluations. A better understanding of how variability in habitual eating behavior impacts sensory perception of foods is needed. The aim of this study was to investigate the effect of habitual eating speed (slow vs. fast eaters) on dynamic sensory perception of composite foods. Habitual oral processing behavior of different composite foods was quantified in 105 participants. Participants were divided in fast (n = 53) and slow (n = 52) eaters using a median split. Three formulations of strawberry jams varying in viscosity and sugar content (High Sugar/Low Pectin [Control], High Sugar/High Pectin, Low Sugar/Low Pectin) were used. Composite foods were prepared by spreading jams on breads. Dynamics of dominant sensory attributes of strawberry jams presented with and without breads were evaluated using Temporal Dominance of Sensations (TDS). Dynamic sensory perception of jams and jam–bread combinations differed only slightly for short periods of time between habitual slow and fast eaters. The addition of breads to jams reduced especially the ability of the fast eaters to discriminate between jams differing in formulation. Slow eaters discriminated between different formulations of jams better than fast eaters, regardless of whether jams were presented alone or in combination with breads. We conclude that differences in habitual eating speed between consumers lead to small differences in dynamic sensory perception and discrimination ability of composite foods.     

Interrelations among physical characteristics,sensory perception and oral processing of protein-based soft-solid structures

Oral processing is essential in breaking down the physicochemical structure of the food and thus important to the sensory perception of food in the mouth. To have an understanding of protein-based, soft-solid texture perception, a multidisciplinary approach was applied that combined studies of food microstructure with mechanical properties, sensory evaluation, and oral physiology. Model foods were developed by combining ion-induced micro-phase separation and protein-polysaccharide phase separation and inversion. Activities of masseter, anterior temporalis and anterior digastric muscles during oral processing were recorded by electromyography (EMG), while jaw movement amplitudes, durations, and velocities were simultaneously collected by a three-dimensional jaw tracking system (JT-3D). Changes in the microstructure of mixed gels significantly altered the characteristics of the chewing sequence, including the muscle activities, number of chews, chewing duration and chewing frequency. Mechanical attributes related to structural breakdown and sensory perception of firmness were highly correlated with the amount of muscle activity required to transform the initial structure into a bolus ready for swallowing. Chewing frequency was linked to mechanical properties such as recoverable energy, fracture strain and water holding capacity of the gels. Increased adhesiveness and moisture release also resulted in slower chewing frequency. Evaluation of oral processing parameters at various stages (i.e., first cycle, first 5 cycles, and last 3 cycles) was found to be a useful method to investigate the dynamic nature of sensory perception at first bite, during chewing and after swallowing. The study showed that muscle activity and jaw movement can be used to understand the links between physical properties of foods and sensory texture.     

Relationships between saliva and food bolus properties from model dairy products

During food consumption, complex oral processing occurs to transform the food into a bolus, ready to be swallowed. The objective of this study was to relate food, saliva and bolus properties, by using model dairy products, to better understand the role of saliva in bolus formation. Un-stimulated and stimulated saliva was collected from 5 subjects and biochemical and enzymatic properties were measured. Food bolus was then obtained from 8 different dairy products, varying in composition and ranging from liquid to gelled samples. The rate of saliva incorporation, pH, spreading ability and bolus rheological properties were determined. Some correlations seemed to exist between lysozyme activity and bolus properties. Subject and food product had a significant effect on almost all bolus properties. The rheology of bolus was highly correlated with food product texture. Even though preliminary, this approach could be used to better understand stimulus release and perception during food consumption.     

The role of oral processing in dynamic sensory perception

Food oral processing is not only important for the ingestion and digestion of food, but also plays an important role in the perception of texture and flavor. This overall sensory perception is dynamic and occurs during all stages of oral processing. However, the relationships between oral operations and sensory perception are not yet fully understood. This article reviews recent progress and research findings on oral food processing, with a focus on the dynamic character of sensory perception of solid foods. The reviewed studies are discussed in terms of both physiology and food properties, and cover first bite, mastication, and swallowing. Little is known about the dynamics of texture and flavor perception during mastication and the importance on overall perception. Novel approaches use time intensity and temporal dominance techniques, and these will be valuable tools for future research on the dynamics of texture and flavor perception.     

Eating behaviour explains differences between individuals in dynamic texture perception of sausages

Texture perception of foods has been demonstrated to be influenced by age, dental health and oral processing behaviour. Eating duration is a significant factor contributing to and determining food oral processing behaviour. The influence of eating duration on dynamic texture perception, oral processing behaviour and properties of the food bolus have not been investigated extensively. The aims of this study are (i) to determine the influence of naturally preferred eating duration on dynamic texture perception of sausages and (ii) to explain differences in dynamic texture perception between short and long duration eaters by chewing behaviour and bolus properties. Two groups of subjects were selected based on their natural eating duration for a controlled portion size of two sausages. The group of “long duration eaters” (n = 11) took on average twice as long to consume a piece of sausage compared to the group of “short duration eaters” (n = 12). Independent of eating duration, short and long eating duration subjects chewed sausages with the same chewing frequency (p = 0.57) and muscle effort rate (p = 0.15) during oral processing. Total muscle effort and total number of chews were significantly higher (p < 0.05 for both) for long duration eaters mainly due to the longer eating time compared to short duration eaters. Bolus properties showed that short duration eaters did not break down the boli as much as long duration eaters resulting in fewer (p < 0.001) and larger (p < 0.05) sausage bolus fragments, firmer (p < 0.001) and less adhesive (p < 0.001) boli with lower fat content (p < 0.05) and less saliva incorporation (p < 0.001) at swallow compared to the bolus properties of long duration eaters. These differences in bolus properties influenced dynamic texture perception of the sausages as the bolus of short duration eaters revealed different properties than the bolus of long duration eaters. Temporal dominance of sensations (TDS) showed that short and long duration eaters perceived the same sausage similarly in the early stages of oral processing, but started to perceive the texture of the same sausage differently from the middle of oral processing towards the end. We conclude that short duration eaters did not compensate for their shorter eating duration by chewing more efficiently but were comfortable swallowing a less broken down bolus than long duration eaters. Moreover, we conclude that differences in eating behaviour between subjects can lead to differences in bolus properties of sausages causing differences in dynamic texture perception of the same sausage.     

Rheological,tribological and sensory attributes of texture-modified foods for dysphagia patients and the elderly: A review

Texture-modified foods (TMFs) and thickened fluids have been used as a therapeutic strategy in the management of food intake in the elderly and people with dysphagia. Despite recent advances in describing rheological features of TMFs for dysphagia management, there is still paucity of research regarding the sensory attributes, therapeutic thickness levels and swallowing safety of these foods. Additionally, the relationship between mechanical and structural properties of TMFs throughout the oral processing is not yet fully understood. The present review discusses several properties of food boluses that are important during oral processing to allow for safe swallowing. Dynamic changes that occur during oral processing of TMFs will be reviewed. The use of hydrocolloids to improve the cohesiveness of TMFs and how this impacts the sensory properties of TMFs will be also discussed. Additionally, this review will suggest potential new research directions to improve textural and sensory properties of TMFs.     

Contribution of temporal dominance of sensations performed by modality (M-TDS) to the sensory perception of texture and flavor in semi-solid products: A case study on fat-free strawberry yogurts

This study aimed to perform Temporal Dominance of Sensations by modality (M-TDS) combined with a multi-intake approach to investigate texture and flavor perception in semi-solid products. Trained panelists (n = 15) evaluated fat-free strawberry yogurts enriched with functional proteins involving texture modifications. As yogurt is a semi-solid product, its in-mouth residence time is short. A multi-intake approach was therefore expected to give more reliable information about the sensory properties perceived by panelists. The two modalities of texture and flavor were analyzed separately to characterize the effect of added proteins. Trials were made according to an experimental design with two factors (protein type and concentration) and three levels each. Different statistical treatments, taking or not the temporality of attributes into account, were performed on standardized and non-standardized data. The implementation of M-TDS was essential to highlight differences of flavor perception in addition to the more evident texture modifications. The study of sensory trajectories evidenced that texture modifications, induced by the use of different whey proteins, slightly modified the perception of flavor and sweetness. The global flavor perception of the samples varied with the number of spoons, which particularly impacted the taste attributes. This study highlighted the importance of using M-TDS when studying texture and flavor in semi-solid products, and the relevance of the multi-intake approach to characterize flavor perception. This methodology enabled panelists to evidence both marked texture differences and subtler flavor modifications, and these useful data were emphasized by combining different statistical treatments.     

Acoustic emission measurement of rubbing and tapping contacts of skin and tongue surfaces in relation to tactile perception

The application of acoustic emission measurement (“acoustic tribology”) is explored for in vivo characterization of rubbing and tapping contacts of the biological tissues of skin and tongue. This acoustic signal originates from physical processes that are closely related to the rapid force fluctuations that are sensed by the rapidly-adapting mechanoreceptors involved in the sensation of touch. Demonstrated is the recording and analysis of sound produced by rubbing and tapping the skin against various surface textures of common materials and by rubbing the tongue against the palate or against food material in the mouth for 1 individual. The technique is shown to be sensitive to skin pre-treatment and pre-meals, and is also shown to discriminate between various surface textures and food materials in a way that relates to perception. The main advantages of the technique are its time-resolution, ease of operation and the fact that it is a direct in vivo measurement of processes that are closely related to texture perception.     

Tribology and its growing use toward the study of food oral processing and sensory perception

Here we provide a comprehensive review of the knowledge base of soft tribology, the study of friction, lubrication, and wear on deformable surfaces, with consideration for its application toward oral tribology and food lubrication. Studies on “soft-tribology” have emerged to provide knowledge and tools to predict oral behavior and assess the performance of foods and beverages. We have shown that there is a comprehensive set of fundamental literature, mainly based on soft contacts in the Mini-traction machine with rolling ball on disk configuration, which provides a baseline for interpreting tribological data from complex food systems. Tribology-sensory relationships do currently exist. However, they are restricted to the specific formulations and tribological configuration utilized, and cannot usually be applied more broadly. With a careful and rigorous formulation/experimental design, we envisage tribological tools to provide insights into the sensory perception of foods in combination with other in vitro technique such as rheology, particle sizing or characterization of surface interactions. This can only occur with the use of well characterized tribopairs and equipment; a careful characterization of simpler model foods before considering complex food products; the incorporation of saliva in tribological studies; the removal of confounding factors from the sensory study and a global approach that considers all regimes of lubrication.     

Exploring how age,medication usage,and dentures effect the sensory perception and liking of oral nutritional supplements in older adults

Sensory perception of Oral Nutritional Supplements (ONS) by older and younger adults has been investigated, but few studies have examined the sensory perception of ONS within different older adult cohorts. This study sought to investigate effects of older age, dentures, and medications on sensory perception, liking, and intake of a high- and low-viscosity ONS (0.009 and 0.177 Pa.s respectively at 50.1 s⁻¹) and assess effects of ONS on appetite.Eighty older adults (51 aged 65–74 years, 29 aged 75 + years, mean age 74 ± 8 years, age range 65–97 years, 35 men, 45 women) evaluated two ONS over two different days. Each ONS (200 mL) was consumed over five sips (40 mL each). The panellists evaluated each sip using a check-all-that-apply questionnaire (CATA) comprising taste and texture attributes. After each CATA evaluation panellists recorded their liking using a 9-point hedonic scale followed by their hunger, fullness, desire to consume more ONS, and thirst using 100 mm visual analogue scales.The over 75 year olds had significantly lower appetite than the 65–74 year olds on tasting both ONS. Denture wearing influenced the mouthfeel while medication status effected the flavour perception of the high viscosity ONS. Liking did not change across the five sips for any study cohort, however, sensory perception changed with increasing sips. This study provides insight on factors affecting ONS adherence in older adults. Avoiding perceptions of watery/runny mouthfeel while maintaining creaminess may improve acceptability and adherence. The study justifies the CATA methodology for use in different older adult cohorts.     

发酵食品加工与贮藏过程中生物胺的控制研究进展

生物胺是在发酵食品及富含氨基酸、蛋白质等强化食品中广泛存在的一类低分子量且具有生物活性的含氮有机化合物,尤其是在发酵食品中,生物胺主要是产胺菌作用于发酵食品,由游离氨基酸发生脱羧反应生成。生物胺的产生会降低食品品质、缩短货架期等问题,摄入过量生物胺会对消费者的身体健康造成威胁。因此,建立安全高效的生物胺控制技术,对于进一步提高发酵食品的质量和安全性具有重要的现实意义。本文在简单介绍生物胺及发酵食品中生物胺形成途径的基础上,重点综述发酵食品在加工和贮藏过程中通过控制原料、改良发酵菌株、人工调控等策略实现生物胺有效控制的研究进展,为发酵食品加工和贮藏过程中生物胺的控制提供解决方案和参考。     

Sensory perception and quality attributes of high pressure processed carrots in comparison to raw, sous-vide and cooked carrots

The application of high pressure processing (HPP) has shown its potential to reduce quality losses of many fruit and vegetable products in comparison to other traditional technologies such as cooking. To identify further opportunities of the application of high pressures in vegetable pieces, the sensory perception and correlation to quality parameters were investigated on carrot sticks (used as model product) submitted to high pressure treatments (600 MPa, 2 min) and compared to other traditional treatments such as sous-vide (90 °C, 5 min), cooked (100 °C, 20 min) and unprocessed (raw). The results indicated that HPP carrots were not different from sous-vide carrots in many parameters such as: sweetness, green flavour and crunchy texture. Furthermore, high pressure carrots showed significantly higher intensity perception of orange colour and fibrousnesses to the rest of the treatments, while similar brightness to cooked carrots and green odour to raw.Throughout 14 days of storage at 4 °C, there was clear evidence that HPP samples could be preserved better in comparison to the rest of the treatments by not presenting any production of acetic acid (used as quality deterioration reference).Overall, sensory evaluation showed correlations to many quality measurements in this study, indicating similarities in hardness versus crunchiness perception and juiciness versus moisture perception between HPP and sous-vide samples. GC/MS and GC/MS-O results were also in agreement in most cases when identifying carrot volatile changes between the different treatments and the identification of the development of new compounds formed.Finally, the tissue structure observed by using Cryo-SEM microscopy, supported the similarities (between HPP and sous-vide) and differences (between treatments) of the quality parameters analysed in this research.

Industrial Relevance

Previous reports on HPP for food applications indicated that this technology will only be commercially successful if added value is achieved or if the product characteristic can be retained at a higher level as compared to thermally/traditionally processed foods. This work provides information on textural and chemical (volatile) changes as well as the sensorial perception of carrots which have undergone high pressure processing, as well as how those changes compare to the quality of both raw and thermally processed carrots. These results may be generally applicable to what could be expected to happen to other ‘hard’ tissue vegetable products produced by high pressure processing, over a refrigerated storage time of 14 days.     

Food oral processing: Mechanisms and implications of food oral destruction

BackgroundFood oral processing is a simultaneous process of food destruction and sensory perception. How a food breaks down its structure inside the mouth and what mechanisms control this process are hugely important to our eating experience and sensory perception. A proper understanding of this process is urgently needed by the food industry for better design and manufacturing of quality tasty food.Scope and approachThis review article analyses research findings from literature and from author's own laboratory in order to identify main controlling mechanisms of food oral destruction. Appropriate experimental evidences are given wherever available to demonstrate the important implications of different destruction mechanisms to sensory perception.Key findings and conclusionsThree major controlling mechanisms of food oral destruction are identified: the mechanical size reduction, the colloidal destabilisation, and the enzymatic interactions. These mechanisms may be applicable to different food materials either independently or collectively. They could also be applicable through the whole eating process or just at a certain stage of an eating process.     

Understanding the oral processing of solid foods: Insights from food structure

Understanding the relationship between the structure of solid foods and their oral processing is paramount for enhancing features such as texture and taste and for improving health-related factors such as management of body weight or dysphagia. This paper discusses the main aspects of the oral processing of solid foods across different categories: (1) oral physiology related to chewing, (2) in-mouth food transformation, (3) texture perception, and (4) taste perception, and emphasis is placed on unveiling the underlying mechanisms of how food structure influences the oral processing of solid foods; this is exemplified by comparing the chewing behaviors for a number of representative solid foods. It highlights that modification of the texture/taste of food based on food structure design opens up the possibility for the development of food products that can be applied in the management of health.     

Changes in the electrical conductivity of foods during ohmic heating

Ohmic heating is a food processing operation in which heat is internally generated within foods by the passage of alternating electric current. The process enables solid particles to heat as fast as liquids, thus making it possible to use High Temperature Short Time sterilization techniques on particulate foods. Ohmic heating rates are critically dependent on the electrical conductivities of the foods being processed, about which little information is available. This paper reports experiments to determine the changes in electrical conductivity which occur during ohmic heating of some common foods. A number of effects which occur during conventional heating, such as starch transition, melting of fats and cell structure changes, are shown to affect the electrical conductivity. In some cases the presence of an electric field induces enhanced diffusion of cell fluids in the food which increases the rate of change of conductivity with temperature above that found by conventional heating. Preheating is found to increase the electrical conductivity of some foods, making them acceptable for ohmic processing.     

Investigating consumers' perception of apple juice as affected by novel and conventional processing technologies

This work evaluates consumers' perception of apple juice processed by high pressure processing (HPP) and pulsed electric field (PEF) compared with thermal processing. As a case study, young Chinese immigrants living in New Zealand were selected. Targeting a broad understanding of process impact, three industrially relevant apple cultivars (New Zealand Jazz, Rose and Granny Smith) were chosen. The consumer study was performed using napping with ultra‐flash profiling technique (n = 38). The process impact on sensory perception seems to vary among the investigated apple cultivars. For Jazz and Granny Smith apple cultivars, PEF‐ and HPP‐treated juices are perceived as fresh, natural, sweet and balanced flavour. For Rose apple cultivar, however PEF‐processed juices appear to be perceived as fresh flavour in comparison with HPP and thermally treated juices. Moreover, thermal processing caused cooked flavour. With respect to colour, immediately after processing, HPP retains the natural apple juice colour compared with other treatments.     

加工条件及关键组分对烘焙食品品质的影响

烘焙食品市场规模巨大且保持着高速增长的趋势。原料组成、加工条件等因素的变化都会对烘焙制品品质产生影响,了解影响烘焙食品质量的因素,对高品质烘焙食品的加工和生产具有重要意义。本文综述了发酵条件、加工工艺、原料组成对烘焙食品品质的影响,其中涉及了对特殊营养成分添加或者低糖、无糖等功能型烘焙食品的研究,这些新型烘焙食品更符合当下人们对营养健康饮食理念的追求,以期为高品质烘焙食品的设计和生产提供参考,促进烘焙食品行业的发展和升级。