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.     

The dynamics of aroma compound transfer properties in cheeses during simulated eating conditions

In vivo aroma release during solid food consumption is a complex phenomenon that depends on food structure and composition, as well as on oral processing (combination of mastication and incorporation of saliva into the food product). The objective of this study was to understand and to predict the physico-chemical properties of aroma compounds through the dynamics of flavor release during in-mouth oral processing of food before bolus swallowing. Within this context, the evolution of two aroma compounds during bolus formation was explored by studying the two main properties that account for mass transfer: air/bolus partition and mass transfer coefficients. Four types of industrial cheese products (varying in fat and firmness) flavored with ethyl propanoate and 2-nonanone were chosen. Each matrix was mixed with various amounts of artificial saliva to mimic boluses at different stages of mastication. The air/bolus partition coefficient was determined by the static phase ratio variation method (PRV), while the mass transfer coefficient was obtained by non-linear regression from dynamic headspace experiments. Results showed that there is a dilution effect on the air/bolus partition coefficient and both a dilution and a product effect (firmness) on the mass transfer coefficient of ethyl propanoate in the bolus. These results were also validated with 2-nonanone for the low-fat cheeses.     

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.     

基于《食品生产许可审查通则(2016版)》及审查细则谈乳制品生产许可现场核查及常见问题

为全面理解乳制品生产相关法令法规和标准,逐步统一审查员的审查尺度,提高企业对乳制品生产规范的认识,本文以《食品生产许可审查通则(2016版)》为框架,结合《企业生产乳制品许可条件审查细则(2010版)》,从6个部分(生产场所、设备设施、设备布局和工艺流程、人员管理、管理制度及试制产品检验合格报告)对食品生产许可现场核查的内容和方法进行细化,并对乳制品生产企业现场核查中缺陷条款进行统计分析,提出相应改进建议,以期审查员能够更好运用食品生产许可现场核查评分记录表,为乳制品生产许可审查工作提供参考。     

Milk-borne infections awareness and the health status of consumers: An on-line survey

Despite clear health risks associated with consuming unpasteurised milk, a considerable number of people are still consuming these products. We evaluated consumers' behaviour and perceptions about food safety risks related to raw milk and unpasteurised cheese product consumption, associating their awareness of foodborne diseases with the epidemiology of gastro-intestinal disorders. A cross-sectional study in Brazil was conducted using an online standard questionnaire. The consumption of raw milk and dairy products is widespread. Although 66% of consumers are misinformed about regulations, 90% of consumers are conscious about the risks of raw milk consumption. The level of awareness of milk-borne diseases is not equal across age and educational level. Although our results should be generalised with caution, we found that awareness of milk-borne diseases is a protective factor against abdominal pain, concluding that the ability to understand the risks of unpasteurised dairy product consumption was associated with health status of the population.     

Parents' implicit perceptions of dairy milk and plant-based milk alternatives

Dairy product consumption is motivated by both familiarity and habit. Milk consumption decreases with age, but milk consumption during childhood and adolescence increases the chances of lifetime milk consumption. Understanding how parents perceive dairy milk and other dairy foods further enables development of dairy-positive messaging that aligns with their perceptions. The objective of this research was to understand parent belief systems around fluid dairy milk and plant-based alternatives (PBA). This goal was accomplished by assessing parents' implicit attitudes toward dairy milk and PBA with an implicit bias exercise (n = 331), followed by qualitative interviews to understand explicitly stated purchase motivations and guided recall of information heard about dairy milk and PBA to better understand external influences on milk perception (n = 88). The majority of parents (73.4%) implicitly associated dairy milk with positive attributes compared with those with a positive association with PBA (13.8%) or with a neutral bias (12.7%). The stronger a parent's implicit bias toward PBA, the more likely they were to purchase these products either alongside or as a replacement for dairy milk. Eighty-five percent of parents in our study could recall drinking milk at home as a child, and 58% remembered encouragement from their parents to drink milk. However, only 38% encouraged their own children to drink milk (the majority, 55%, were neutral toward their children's milk consumption). Generally negative media messaging toward dairy milk and positive messaging toward PBA may contribute to this trend, even if consumers are not explicitly aware of their perception changes. Seventy-seven percent of parents felt generally confident in choosing dairy milk or PBA for their children. However, only 26% of parents felt that nothing about dairy milk or PBA information or messaging was confusing. Sources of uncertainty about dairy milk included hormones and antibiotics, animal welfare, ecological sustainability, potential contamination, and intolerances or allergies. By addressing the most commonly encountered and recalled concerns about milk from parents, dairy producers may be able to increase trust and implicit bias toward dairy milk compared with PBA.     

Nonbovine milk and its products as sources of probiotics delivery: An overview of its viability,functionality and product quality characteristics

Dairy products are the most predominant food carriers for probiotics, providing adequate therapeutic and functional benefits to the host when sufficient probiotics are maintained. Bovine milk currently dominates the global probiotic food market, but there is an increasing trend of applying nonbovine milk from other dairy animals as probiotic carrier food matrices as described in this review. Nonbovine dairy products can be considered suitable food matrices for probiotic delivery due to their excellent probiotic viability (mostly >log 7 cfu/mL or g) during shelf life, functional properties and product quality characteristics, being considered desirable and novel dairy products.     

Short communication: Detection of undeclared presence of bovine milk in buffalo yogurt

The authenticity of buffalo (Bubalus bubalis) dairy products is a focal issue, considering the increasing demand for buffalo milk products. Therefore, the aim of this study was to investigate the undeclared presence of bovine (Bos taurus) milk in buffalo yogurt, to understand which risk factors might make the product vulnerable to fraud. Real-time PCR assay showed the undeclared presence of bovine DNA in addition to buffalo DNA in 18 of 72 samples. Given the widespread lack of data on the presence of undeclared milk species in buffalo dairy products, the study provides a significant insight into the incidence of fraud in the buffalo dairy field. The data from this study could help improve the analysis of food safety risks along the buffalo milk supply chain and in the dairy processing industry, perceived as being highly vulnerable to food fraud, and prioritize target areas for food policy making to steer and enforce European food fraud regulations.     

Use of ultrasound for characterizing dairy products

It has been known for a long time that acoustic measurements offer some unique features for characterizing liquid food products in their intact state, without any preparation or destruction of the product sample. Acoustic characterization can yield information about fat content, droplet size distribution, and kinetics of product variation with time. Furthermore, acoustic methods are very attractive for on-line process control. This paper addresses several questions: Why does ultrasound attenuate when propagating through a heterogeneous system? What properties of dairy products can be extracted from such ultrasound measurements? Which measurement is better for product characterization: attenuation or sound speed? What measurement precision is required to adequately characterize product properties? What frequency range is of most value for determining these product properties?It is possible to provide answers to many of these questions using experimental data, thereby avoiding, for the moment, any complex mathematical analysis. We present several applications of acoustic spectroscopy for characterizing dairy products, including characterization of the fat content in a wide variety of dairy products; calculation of the fat droplet size distribution in milk without dilution; and calculation of water droplet size in butter, without dilution or melting.     

Rice bolus texture changes due to α-amylase

During mastication, starch hydrolysis caused by salivary α-amylase may influence food bolus formation and subsequent breakdown during gastric digestion. The objective of this study was to examine texture changes of rice boluses after simulated mastication. Boluses were prepared with three varieties each of brown and white rice (short, medium, and long grain). After simulated mastication, rice boluses were incubated from 0 to 180 min at 37 °C prior to texture measurement by bulk compression. Saliva was added at concentrations of 0.1 and 0.2 mL saliva/g rice. Boluses were also formed with 0.1 mL/g saliva without α-amylase. The peak force and area under the compression curve were significantly influenced by rice type, saliva level, and incubation time (p < 0.0001). The peak force of the boluses decreased, on average, from 127 to 52 N for brown rice and 111 to 54 N for white rice. Changes in bolus texture were described by a linear-exponential model. For all rice types, bolus texture was significantly lower in the presence of α-amylase. Saliva amount and presence of α-amylase influenced the textural properties of rice boluses during 180 min of incubation. These factors should be carefully considered in future in vitro studies of carbohydrate-based food products.     

Dairy products and inflammation: A review of the clinical evidence

Inflammation is a major biological process regulating the interaction between organisms and the environment, including the diet. Because of the increase in chronic inflammatory diseases, and in light of the immune-regulatory properties of breastfeeding, the ability of dairy products to modulate inflammatory processes in humans is an important but unresolved issue. Here, we report a systematic review of 52 clinical trials investigating inflammatory markers in relation to the consumption of dairy products. An inflammatory score (IS) was defined to quantitatively evaluate this interaction. The IS was significantly positive for the entire data set, indicating an anti-inflammatory activity in humans. When the subjects were stratified according to their health status, the IS was strongly indicative of an anti-inflammatory activity in subjects with metabolic disorders and of a pro-inflammatory activity in subjects allergic to bovine milk. Stratifying the data by product categories associated both low-fat and high-fat products, as well as fermented products, with an anti-inflammatory activity. Remarkably, the literature is characterized by a large gap in knowledge on bioavailability of bioactive nutrients. Future research should thus better combine food and nutritional sciences to adequately follow the fate of these nutrients along the gastrointestinal and metabolic axes.     

Invited review: Potential effects of short- and long-term intake of fermented dairy products on prevention and control of type 2 diabetes mellitus

The consumption of fermented dairy products has been linked with lowering the risk of type 2 diabetes mellitus (T2DM), but studies have yet to demonstrate a definite association. We evaluated evidence from a cross-sectional analysis of longitudinal studies and human and animal experimental trials to further understand the current knowledge linking short- and long-term consumption of fermented dairy products to T2DM. Most cohort studies revealed a protective effect of fermented dairy products on T2DM development, with yogurt noted as the most consistent food item protecting against the disease. Human experimental trials and animal studies revealed improvements in biomarkers of glycemic control with short-term monitored intake of fermented dairy products from various sources. Therefore, fermented dairy products may offer protection against the development and may have therapeutic benefits for individuals with T2DM. This could influence on dietary recommendations and the development of functional foods aiming to minimize the risk of T2DM.     

河北省居民乳制品消费研究

通过对河北省居民乳制品消费量、消费品种、消费群体和消费地域的现状分析,提出了对策和建议。期望能对河北省乳制品消费趋势以及奶牛养殖规划和乳品行业发展规划的制定起到一定的借鉴作用。     

Food oral processing—A review

Food oral processing is an essential procedure not only for the consumption and digestion of foods but also for the appreciation and pleasure of food texture and food flavour. The consumption of a food inside mouth involves various oral operations, including first bite, chewing and mastication, transportation, bolus formation, swallowing, etc. Exact mechanisms and governing principles of these oral operations are still not fully understood, despite of continuous efforts made by scientists from food, psychology, physiology, dental and clinical studies, and other disciplines. This article reviews recent progresses and literature findings about food processing and transformation in mouth, with particular attention on the physiology and rheology aspects of oral operations. The physiological behaviour of human's oral device is discussed in terms of biting capability, tongue movement, saliva production and incorporation, and swallowing. The complexity of oral processing is analysed in relation to the rheology and mechanical properties of foods. The swallowing and oral clearing process is also examined for its criteria, triggering mechanism, bolus deformation, and the rheology of swallowing.     

Associations of diet with body burden of dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs): observations on pregnant women from central Taiwan.

The aim of this study was to examine the relationship between placental polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/F) and polychlorinated biphenyls (PCBs) toxic equivalent (TEQ) levels and the consumption of various food types in pregnant women from central Taiwan. Placental PCDD/Fs and PCB congener TEQ levels were evaluated in 109 pregnant women and dietary information was obtained by questionnaire. TEQ levels of PCDD/Fs and PCBs were positively associated with age and annual family incomes (p < 0.05). PCDD/F TEQs were significantly associated with freshwater fish and dairy product consumption after adjustment for age and body mass index (BMI) (p < 0.05). For PCB TEQs, significant associations were detected for saltwater fish consumption (p < 0.05). In summary, positive correlations were found between freshwater fish and dairy product intake and PCDD/F levels, and a marginal correlation between saltwater fish intake and the body burden of PCBs in pregnant women from central Taiwan. Risk assessment of PCDD/Fs and PCB in fishery products is warranted in a future study to quantify the benefits of fish consumption during the perinatal period.     

应用Illumina MiSeq测序技术比较传统发酵乳、肉食品中细菌多样性

为全面了解内蒙古特色发酵食品中细菌微生物多样性,比较不同发酵食品的细菌群落结构。运用高通量测序技术,对发酵乳制品(饼状奶酪、棒状奶酪及奶豆腐)和发酵肉制品(发酵香肠、风干羊肉和风干牛肉)中细菌群落组成和多样性进行分析。本研究中共获得194568条有效序列,237个OTU。菌群多样性分析表明:发酵肉制品中菌群Shannon指数较高于发酵乳制品,乳肉制品之间的菌群组成差异较大。发酵乳制品中主要以厚壁菌门为主,而发酵肉制品则以厚壁菌门和变形菌门为主;在属水平上,发酵乳制品的优势菌属为乳杆菌属,而发酵肉制品中的优势菌属为假单胞菌属,次优势菌属为乳杆菌属。在种水平上,由于未检测到的菌群含量较高,所以不能确定乳、肉制品优势菌种,而在发酵乳、肉食品中可检测到的菌群中清酒乳杆菌含量较高。通过16s预测功能分析,发酵乳、肉食品中的绝大部分细菌与转运代谢有关,如脂肪代谢、氨基酸代谢等功能。     

Prevalence of Listeria monocytogenes and Salmonella in ready-to-eat food in Catalonia, Spain

Listeria monocytogenes and Salmonella are pathogenic bacteria that can contaminate food products during or after processing. Ready-to-eat (RTE) food does not undergo any treatment to ensure its safety before consumption, and therefore risk of foodborne disease must be considered if these pathogens are present in the food. To evaluate the prevalence of these pathogens in RTE food, 140 RTE fish product samples, 501 RTE meat product samples, 462 RTE dairy samples, and 123 RTE dishes and desserts, providing a total of 1,226 samples, were collected from retail stores and food industry and analyzed for the presence of L. monocytogenes. A total of 1,379 samples consisting of 187 RTE fish products and 569 RTE meat products, 484 RTE dairy products, and 139 RTE dishes and desserts were collected and analyzed for the presence of Salmonella. L. monocytogenes was isolated from 20% of frozen Atlantic bonito small pies, 7.9% of smoked salmon samples, 11.1% of the pork luncheon meat samples, 6.2% of frozen chicken croquettes, 16.9% of cured dried sausage samples, 12.5% of cooked ham samples, and 20% of cooked turkey breast samples. L. monocytogenes was also found to be present in 1.3% of fresh salty cheese samples and 15.1% of frozen cannelloni samples. Salmonella was isolated from 1.2% of smoked salmon samples, 1.5% of frozen chicken croquettes, 2% of cooked ham samples, and 11.1% of cured dried sausage samples. Overall, occurrence of these pathogens in RTE foods was similar to that previously reported in the literature.     

Swallowing profiles of food polysaccharide gels in relation to bolus rheology

Swallowing profiles of food polysaccharide gels were investigated in relation to bolus rheology. Polysaccharide gel from either gellan gum or a mixture of gellan gum and psyllium seed gum was used as a model food. Acoustic analysis and sensory evaluation were carried out to investigate the swallowing profiles using the same human subjects. Model bolus was prepared through instrumental mastication using a mechanical simulator to mimic the action of the human jaw in the presence or absence of artificial saliva and was subjected to dynamic viscoelasticity measurements to investigate the rheological properties. Bolus from the binary gel was shorter in time required to transfer through the pharyngeal phase due to mass flow and was scored higher in sensory perceived cohesiveness (bolus forming) than that from gellan gum gel. Model bolus from the binary gel showed a rheologically weak gel (or structured fluid) behavior and was higher in structural homogeneity than that from gellan gum gel. Also, dynamic viscoelasticity parameters of the binary gel were less dependent on the addition level of saliva. Results indicate that the viscoelasticity balance is a key for texture design of dysphagia foods in relation to the saliva miscibility.     

Recent Development in Osmotic Dehydration of Fruit and Vegetables: A Review

Osmotic dehydration of fruits and vegetables is achieved by placing the solid/semi solid, whole or in pieces, in a hypertonic solution (sugar and/or salt) with a simultaneous counter diffusion of solutes from the osmotic solution into the tissues. Osmotic dehydration is recommended as a processing method to obtain better quality of food products. Partial dehydration allows structural, nutritional, sensory, and other functional properties of the raw material to be modified. However, the food industry uptake of osmotic dehydration of foods has not been extensive as expected due to the poor understanding of the counter current flow phenomena associated with it. However, these flows are in a dynamic equilibrium with each other and significantly influence the final product in terms of preservation, nutrition, and organoleptic properties. The demand of healthy, natural, nutritious, and tasty processed food products continuously increases, not only for finished products, but also for ingredient to be included in complex foods such as ice cream, cereals, dairy, confectionaries, and bakery products.