LIQUID TEXTURE PERCEIVED IN THE MOUTH1

Statistical analysis of subjective assessments obtained by ratio scaling suggested that a ten attribute vocabulary describing liquid texture in the mouth could be reduced to a smaller number without great loss of predictive power, Three attributes, “thickness,”“smoothness,” and “slipperiness,” which could best predict the remaining seven were selected for further study. Each attribute was found to be closely related to a specific force in the mouth. “Thickness” was shown to be proportional to the viscous force between the tongue and the roof of the mouth. “Smoothness” seemed to be inversely proportional to the frictional force caused by the contact between the tongue and the mouth. “Slipperiness” was shown to be inversely proportional to a known average of viscous and frictional forces.     

Food neophobia among the Finns and related responses to familiar and unfamiliar foods

A representative sample of the Finns (n=1083) rated the familiarity of 20 foods designated to be “familiar” or “unfamiliar” and willingness to try them. Subjects also filled in a 10-item questionnaire measuring their individual food neophobia. Food neophobia scores decreased with increasing education and with the degree of urbanization. Men were more neophobic than women, and the elderly (66–80 years) were more neophobic than the other age groups. Subjects with high food neophobia were less likely to have tasted or eaten the rated foods than were those with low food neophobia. Food neophobia significantly predicted the willingness to try “unfamiliar”, and also some “familiar” foods. In factor analysis, the items of the food neophobia scale loaded on two factors but the variance was mainly explained by the first factor related to the interest in new foods. The second factor may reflect a general concern about trying unknown foods. Overall, the translated food neophobia scale appeared to be a valid instrument for the characterization of consumer responses to unfamiliar foods.     

Identification of Key Textural Attributes of Fluid and Semi-Solid Foods Using Regression Analysis

Regression analysis was used to identify key attributes from 15 textural terms generated by a panel for 27 fluid and semi-solid commercial foods. A search using single independent variables showed that “thick” gave the best average R² with a value of 0.548; a search with two independent variables showed that “thick” and “soft” gave the best average R² of 0.748; a search with three attributes showed that “slippery”, “thick,” and “soft” gave the highest R² values of 0.803. The final equations provided a set of regression parameters which can be used to predict twelve textural attributes from scores obtained for “thick”, “soft”, and “slippery”.     

THE SENSITIVITY OF DIFFERENT BREWING YEAST STRAINS TO CARBON DIOXIDE INHIBITION: FERMENTATION AND PRODUCTION OF FLAVOUR-ACTIVE VOLATILE COMPOUNDS

The sensitivity of brewing yeast strains, with different oxygen demands, to carbon dioxide inhibition was investigated. Laboratory fermentations were performed with, and without, protein-based “yeast foods” to lower dissolved CO₂ during fermentation. Differences were observed in yeast fermentative performance in the presence and absence of “yeast foods” for all yeast strains tested. Fermentation performance was improved with the addition of “yeast foods”. There was improved carbohydrate utilisation and amino acid uptake, while acetaldehyde levels at the end of fermentation were decreased. There was an increase in fusel oil production and acetate ester levels at the end of fermentation. Sulphur dioxide levels at the end of fermentation were unaffected by “yeast food” addition. Different yeast strains displayed differing sensitivity to CO₂ inhibition for all parameters tested. Sensitivity to CO₂ was not found to be related to oxygen demand of the yeast strains.     

Children’s selection of emojis to express food-elicited emotions in varied eating contexts

Emojis were suggested for children to be used to measure food-elicited emotions. The present study was aimed to explore the appropriateness of emojis to describe pre-adolescents’ emotions elicited by foods recalled in relation to different evoked eating contexts and to explore related age- and gender differences. Fifty-five boys and forty-one girls aged 9–13 participated to the study. First, subjects were asked to recall, by means of an open-ended question, the foods they had in specific eating contexts: “Most liked food” and “Most disliked food”, “Breakfast”, “Dinner”, “Snack”, “Birthday” and “Novel food”. Then, they were asked to select the emojis appropriate to describe their feelings for the context-related foods by selecting from a list of 92 facial emojis (CATA method). Emojis selected by more than 20% of children in at least one eating context qualified as food-related. In total, 46 emojis resulted as appropriate to describe emotions in different eating contexts. Pre-adolescents used mainly positive emojis, except for the context “Most disliked food”, where mainly negative emojis were used. Most food-related emojis resulted from “Most liked food” and “Most disliked food”, but the context “Birthday” also added some context-specific emojis. The number of selected emojis varied across evoked eating contexts eliciting different foods. Age and gender significantly affected emoji selection across and within foods elicited by varied eating contexts, with girls and 9–11-year-old subjects selecting some emojis more frequently across all contexts, but also within contexts. The approach used in the present study has the potential to be used for the development of a food-related emotion measurement tool for pre-adolescents. Future research aimed at interpreting the meaning of facial emojis is needed and should consider age- and gender differences.     

Organic food

“Organic” or “organically grown” foods are commonly represented as “food grown without pesticides; grown without artificial fertilizers; grown in soil whose humus content is increased by the additions of organic matter; grown in soil whose mineral content is increased with applications of natural mineral fertilizers; which has not been treated with preservatives, hormones, antibiotics, etc.” The substitution of “organic” for “chemical” fertilizers during the growth of plants produces no change in the nutritional or chemical properties of foods. All foods are made of “chemicals.” Traces of pesticides have been reported to be present in about 20 to 30% of both “organic” and conventional foods. These traces are usually within the official tolerance levels. Such levels are set low enough to protect consumers adequately. Indeed, there is no record of a single case of injury to a consumer resulting from the application of pesticides to food crops at permitted levels. There is no method for distinguishing between “organic” and conventional foods. The use of the term “organic” is a promotional device. Prices of “organic” foods tend to be higher than those of their conventional counterparts. A series of controlled tests showed that conventional foods were superior to corresponding “health foods” in terms of odor, color, texture, and flavor.     

Defining and characterizing the “nutty” attribute across food categories

The term “nutty” has been used to describe a vast array of foods including many foods outside the realm of nuts. However, it is not clear if “nutty” is a single term or if it takes various forms, depending on the type of product. The objective of this study was to determine whether a single nutty term could be used to describe nuttiness in all food products or if additional terms were needed. More than 200 products with potential nutty flavor, including nuts, nut spreads, grains/cereals, seeds, beans/legumes, oils, cheeses, fish, and beverages, were studied. Five “nutty” concepts were found and described with terms, definitions, and references with intensity ratings: overall nutty, nutty-beany, nutty-buttery, nutty-grain-like, and nutty-woody. Four of those attributes, excluding overall nutty, were single concept attributes that described subgroups of nuttiness. Specific terms, such as peanut or almond, that describe a certain type of nut but are separate from the “nutty” character were excluded intentionally because they do not describe nutty, they describe an overall concept flavor beyond nutty. A second panel of trained assessors was used to review the lexicon. This panel used this lexicon to describe a set of 10 products (nuts, grains, beans, seeds, cheeses) and determine if any additional attributes were needed to describe nuttiness. All of the products displayed varying intensities of the nutty attributes and the panel found no additional terms for the “nutty” component were needed. The development and verification of the lexicon has real-world application because it can assist in product development and quality assurance when describing foods with a “nutty” attribute. These terms can be applied across all food categories and is not exclusive to characterizing nuts.     

A rapid method to evaluate the chocolate smoothness based on the tribological measurement

Cocoa is the primary ingredient in chocolate, and cocoa concentration attributes to the smoothness of the chocolate. Supporting this statement, we assessed the smoothness and melting properties of five chocolates of different cocoa concentration from three brands using the professional sensor evaluation and weight method, respectively. Artificial saliva was added to obtain the mixed chocolate solutions, and their viscosity and coefficient of friction (CoF) were measured for three rubbing pairs. The correlation of chocolate smoothness with their viscosities and average CoF (aCoF) was also discussed. The results indicated that the cocoa concentration significantly affected the smoothness of the chocolates among the three brands. The mixed solution of 50% chocolate could be a representative of oral processing, but their viscosities were not proficient enough to effectively characterize their smoothness. The aCoF of 50% chocolate solution could be rapid and effective to evaluate their smoothness. In addition, the Two-GCTPE rubbing pair was more suitable way to evaluate the smoothness of similar foods in the oral environment. The study results will provide a better insight into characterizing certain attribution of similar foods.     

What is satiating? Consumer perceptions of satiating foods and expected satiety of protein-based meals

Designing food items with high satiating capacity is an area of increasing interest. It would be desirable for consumers to be able to make informed choices about individual products based on understanding the energy balance and the meaning of satiety.In the present work, the perceptions that consumers have of the word “satiating” and of different protein-based dishes were investigated in two populations (100 subjects related to the field of food science and technology and 100 unrelated to it). The Word Association (WA) technique was used, asking the consumers for the first four words that came into their mind when they thought of “satiating food”. This was followed by a Free Listing (FL) exercise that asked them to list four satiating food items. They also completed a Nutritional Knowledge Questionnaire. To evaluate the consumers' perception of the expected satiating capacity of different protein-based meals, they were shown eight photographs of equicaloric dishes composed of one piece of protein (beef, pork, chicken or fish) and one of two different side vegetables (salad or boiled potatoes). The expected satiety scores ranked fish last among the protein foods and potatoes last among the side vegetables. The results indicated that “satiating” food was related more with the immediate sensation of “stomach full” than with the cessation of hunger. This was reinforced by the mention of negative sensations of discomfort after a copious meal. Hearty dishes and meat were the meals most associated with satiating food items.     

Assessing Palatability Characteristics of Beef Destined for Retail Distribution

Beef strip loins (n=723) were obtained from nine different suppliers and were evaluated for certain quality-indicating characteristics and fat thickness. After detailed sensory evaluation, several differences in palatability were found when comparing all suppliers. When stratified according to marbling and fat thickness, those steaks with marbling scores of “Slight-minus” regardless of fat thickness received the lowest ratings.     

Comparison of Global Food Traceability Regulations and Requirements

The food traceability regulations of 21 Organization for Economic Co‐Operation and Development (OECD) countries were examined with attention to whether these regulations are comprehensive for all food commodities and processed foods. The countries were evaluated based on responses to a series of questions that were developed to allow assessment of their traceability programs. The questions sought background information on whether: mandatory traceability regulation(s) exists at the national level within a given country; regulations include imported products, and the nature of required documentation for imports; an electronic database(s) for traceability exists and, if present, its accessibility; and labeling regulations allow consumer access and understanding of traceability. The examination ranked the countries that have specific traceability regulations for all commodities, both domestic and imports, as “Progressive,” while countries with less broad or stringent regulations were ranked as “Moderate,” and countries that were still in the developmental stage of mandatory or industry‐led traceability requirements were ranked as “Regressive.” Aggregate scores were developed from all of the rankings, determined on the basis of the questions, for each of the 21 countries, to provide an overall world ranking score. The aggregate scores were “Superior,” “Average,” or “Poor.”     

The physical basis of liquid food texture and texture-taste interactions

This paper reviews recent efforts, mostly at the author's laboratory, to relate liquid and semi-solid texture to rheological and frictional properties and to relate texture-taste interactions to diffusion coefficients.First, the large texture vocabulary is reduced to a few key attributes of ‘thick’, ‘smooth’ and ‘slippery’ using statistical analysis. A model is presented approximating the deformation process and capable of predicting shear stress in the mouth, which is solved for Newtonian, ‘non-Newtonian’ and ‘non-Newtonian foods with time dependent rheology’. Shear stress is then related to magnitude estimation of ‘thickness’. Similar approaches lead to prediction of ‘spreadability’ using a knife.‘Smoothness’ is shown to be related to the inverse of the friction force required to have skin slip across skin or food, and ‘slipperiness’ is shown to be related to the inverse of the sum of viscous and frictional forces. ‘Creaminess’ is shown to be predicted from scores of ‘thickness’ and ‘smoothness’.Viscosity-taste interactions are explained by assuming that the rate of diffusion of tasting agent to the surface of the tongue is slower than the rate of the taste reaction responsible for the intensity of a tasting reaction. Therefore, the ‘flux’ of tasting agent controls the rate of the tasting reaction. The penetration model of mass transfer suggests that this flux is proportional to the square root of the diffusion coefficient. This concept is shown to explain viscosity-taste interactions.     

Determination of 12 herbal compounds for estimating the presence of Angelica Gigas Root,Cornus Fruit,Licorice Root,Pueraria Root,and Schisandra Fruit in foods by LC-MS/MS

ABSTRACT

A wide variety of plant raw materials thought to promote health are used as herbal medicines as well as foods. However, there is no legal maximum or minimum concentration limit on any herbal compound when these plant raw materials are used in processed foods. Legally, these processed foods are regulated only for harmful substances, and there is no other guarantee of their contents. Therefore, the objective of this study was to determine the concentrations of 12 herbal compounds (nodakenin, decursin, decursinol angelate, morroniside, loganin, glycyrrhizic acid, liquiritigenin, puerarin, daidzin, schisandrin, gomisin A, gomisin N) in commonly used plant raw materials, such as “Angelica Gigas root”, “Cornus Fruit”, “Liquorice Root”, “Pueraria Root”, and “Schisandra Fruit”; and also in 45 processed foods, using high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). Method validation was performed successfully using the parameters of specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, precision, matrix effect, extraction recovery, and stability. The 12 herbal compounds were determined to be present in all the foods advertised as containing each ingredient, although in very low concentrations in some cases. Three solid samples labelled as 100% pure material from one herbal species also contained herbal compounds found in others, so that intentional or unintentional adulteration was suspected.     

A sensitive monoclonal-antibody-based test for gluten detection: Quantitative immunoassay

An enzyme-coupled monoclonal antibody has been used to quantify “gliadin-like immunoreactivity” in a variety of foods. Small discs of nitrocellulose are soaked in food extract or a series of standard gliadin solutions, and incubated with antibody and an enzyme substrate yielding a soluble product. By use of a photometer, standard curves for gliadin may be constructed and the apparent gliadin content of samples calculated. The reproducibility and reliability of the procedure were examined using a variety of common foods and food proteins. The limit of detection for wheat gliadin was approximately 20μg/ml extract; gliadin levels in excess of this value were found in some “gluten-free bread mixes” and starch sources. The overall time for analysis is 5–6 h, although for large numbers of samples, overnight blocking of non-specific antibody binding may be used. It is possible that a “library” of enzyme-linked monoclonal antibodies could be developed as useful tools for specific food analysis.     

How is satisfaction with food-related life conceptualized? A comparison between parents and their adolescent children in dual-headed households

Satisfaction with food-related life (SWFRL) is one component of satisfaction with life. Although researchers have identified associations between satisfaction with food-related life and specific food behaviours, it is still not clear how consumers conceptualize this complex construct. The aims of the present study were to explore consumers’ conceptualization of SWFRL, to compare how parents and adolescents in dual-headed households perceive SWFRL, and to identify aspects that would increase their SWFRL. One-hundred and sixty-four dual families composed of mother, father, and at least one adolescent child between 10 and 17 years of age participated in the study. They completed a word association task with “Being satisfied with my food-related life” and completed the sentence “I would be more satisfied with my food-related life if…”. Participants’ responses were aligned with the formal definition of SWFRL. References to specific foods and food characteristics were also mentioned in the word association task. No significant differences were found between parents and adolescents in the frequency of mention of responses related to the identified categories and supra-categories, suggesting lack of differences in their conceptualization of SWFRL. Changes in eating behaviours and individuals’ resources for purchasing and preparing foods were regarded as the main factors that could increase SWFRL. Differences between family members were found in some of the aspects associated with an increase in SWFRL. Results from this study can aid in the development of strategies for promoting changes in eating habits and increasing SWFRL, targeted at different family members.     

Opinion of Spanish Consumers on Hydrosustainable Pistachios

Fruits and vegetables cultivated under controlled deficit irrigation (CDI) are called hydrosustainable (hydroSOS) products and have its own personality and are environmentally‐friendly. Focus groups helped in classifying key farming, sensory, and health concepts associated with CDI‐grown pistachios. Besides, focus groups also helped in stating that a logo was needed for these special foods, and that a hydroSOS index is also essential to certify that the products have been controlled by a control board. Conjoint analysis was used to check which attributes could be helpful in promoting CDI‐grown pistachios among Spanish consumers in a 1st step toward the European Union (EU) market. It was clearly proved that the main silo of properties driving the attention of Spanish consumers was that related to health. The most important attributes for pistachios were “product of Spain,” “rich in antioxidant,” and “crunchy”; this finding was clearly related to the popularity of regional foods, the preoccupation of European consumers for their health, and the joy related to the crunchiness of toasted nuts, respectively. The use of these 3 concepts, together with the use of the hydroSOS logo, will be essential to promote hydroSOS pistachios among Spanish and EU consumers. Finally, it is important to highlight that in general Spanish consumers were willing to pay an extra amount of 1.0 euros per kg of hydroSOS pistachios. These earnings will be essential to convince Spanish farmers to implement CDI strategies and have a sustainable and environmental‐friendly use of the irrigation water.     

Determination of chemical hazards in foods using surface-enhanced Raman spectroscopy coupled with advanced separation techniques

BackgroundSurface-enhanced Raman spectroscopy (SERS) has been validated as a highly accurate and specific technique for the discrimination, identification, and potential quantification of different types of chemical compounds. However, its application for the detection of potential hazardous chemical targets in foods has not yet been well developed due to interferences from the complicated food matrices, which could lead to challenges in spectral deconvolution and interpretation. The accurate separation and enrichment of the analyte from food samples are major challenges for analytical chemists and food technologists.Scope and approachFour promising “capturing” techniques (molecularly imprinted polymers, aptamer, antibody, and microfluidics) coupled with SERS were introduced in this review paper for the reliable and ultrafast determination of chemical hazards in food systems. These developed “one-step” or “two-step” SERS methods can achieve accurate and sensitive detection of trace level chemical hazards in agricultural products including foods.Key findings and conclusionsTandem SERS methods can be applied for rapid and reliable detection of trace level of chemical hazards in foods.     

Correlation of microbial response in model food systems with physico-chemical and “mobility” descriptors of the media

The role played by water activity (a_w), “mobility” (“molecular” by Nuclear Magnetic Resonance (NMR) analysis and “macromolecular”, by glassy to rubbery transition, thermal analysis) and physico-chemical properties of the media in modulating microbial response have been studied in multicomponent model food systems of different physical state. NMR “molecular” mobility correlated well with microbial (mold spore) response in solid and semisolid systems (dry and intermediate moisture foods) while in high moisture, liquid, homogeneous systems water activity was found to correlate better with Staphylococcus aureus activity. Correlation between microbial survival ability and glassy to rubbery transition in heterogeneous and complex model systems is not yet conclusive.Industrial relevanceFood technologists, in order to assure safety and stability of food products, should understand the relevant factors in microbial activity. Water availability is a fundamental principle in food preservation and it might be related to water mobility. Mold spoilage, has been shown to be closely related to water mobility (in this case, measured by NMR). However, in some systems, when humectants are used, water activity is an important empirical parameter in food preservation involving intermediate moisture foods. In this work, the role played by “mobility” (“molecular” by NMR analysis and “macromolecular”, by glassy to rubbery transition, thermal analysis) was analyzed in food model systems and an important role of “water mobility” was suggested.