Consumption of edible insects and insect-based foods: A systematic review of sensory properties and evoked emotional response.

Low consumer acceptance of edible insects and insect-based products is one of the main barriers to the successful implementation of entomophagy in Western countries. This rejection is mainly caused by consumers' negative emotional responses, psychological/personality traits, and attitudes toward food choices. However, as the role of intrinsic product characteristics on such food choices has not been adequately studied, a systematic review was conducted following the PRISMA method, to analyze studies that have assessed hedonic evaluations, sensory profiling, or emotional responses to edible insects or insect-based products. The majority of studies performed with whole insects and insect flour highlight that insect-based products are more negatively evaluated than control products. Although the sensory properties of insects are affected by species and processing conditions, they are generally negative across sensory dimensions. In particular, insects and insect-based products are generally associated with odor and flavor/taste attributes that are related to old/spoiled food. These negative attributes can be linked to the fat fraction of edible insects, with insect oils being very negatively evaluated by consumers. On the other hand, defatted fractions and deodorized oils are not associated with these negative attributes, further supporting the hypothesis that the fat fraction is responsible for the negative odor and flavor/taste attributes. However, there is still a lack of studies assessing the sensory profile of edible insects and insect-based products, as well as consumers' emotional responses to their consumption. Future studies should focus on the effects of different processing conditions, products incorporating insect fractions (namely protein concentrates/isolates and defatted fractions), and evaluation by target consumer groups.

School lunch nutritional adequacy: what is served, consumed and wasted.

OBJECTIVE: To determine nutritional adequacy of school lunch and to assess the impact of food waste on nutrient intake of primary schoolchildren. DESIGN: The weighing method was used for evaluating initial servings and plate waste for lunch. Energy and nutritional contents of meals served, consumed and wasted were estimated using the software Food Processor Plus. The mean nutritional value of food served and consumed was compared with dietary guidelines. SETTING: Portuguese public primary schools in the city of Porto. PARTICIPANTS: All 525 fourth-grade children, aged from 9 to 10 years old, attending to twenty-one public primary schools. RESULTS: Overall, school lunches served did not meet the dietary guidelines for energy and nutrients, as only 12·5 % of the evaluated meals were adequate for energy, 33·5 % for proteins, 11·9 % for carbohydrates and 57·1 % for lipids. The majority of meals served were below the age-specific lower limit, namely for energy (83·7 %) and carbohydrates (86·8 %). The only exception, also unbalanced, was observed for proteins, as 42·4 % of lunches served exceeded the recommended upper limit. Furthermore, lunches served and consumed by children did not meet the dietary guidelines for fibre and for the micronutrients evaluated. Children wasted 26 % of the energy content provided in lunches, corresponding to 91·5 kcal, 25 % of proteins and 29 % of carbohydrates supplied. CONCLUSIONS: The lunches served and consumed by children at school canteens failed to meet nutritional standards. These results are not only a consequence of inadequate food portions served but also a result of the high plate waste values observed.

Strategies to reduce plate waste in primary schools - experimental evaluation.

OBJECTIVE: To determine and compare the effect of two interventions in reducing the plate waste of school lunches. DESIGN: A between-group analysis was conducted among children from three primary schools: (i) a group receiving intervention A, designed for children and focusing on nutrition education and food waste; (ii) a group receiving intervention B, intended for teachers and focusing on the causes and consequences of food waste; and (iii) a control group with no intervention. For each child, physical weighing of individual meals and leftovers was performed on three non-consecutive weeks at baseline (T0), 1 week (T1, short term) and 3 months (T2, medium term) following the intervention. Plate waste was recorded for a total of 1742 lunches during 14 d over eight different menus. SETTING: Portuguese public primary schools in the city of Porto. SUBJECTS: All fourth-grade children (n 212) attending the three preselected schools. RESULTS: After intervention A focusing on nutrition education designed for children, a decrease in soup waste was observed compared with the control group. The effect was greater at T1 (-11·9 (se 2·8) %; P<0·001) than at T2 (-5·8 (se 4·4) %; P=0·103). The plate waste of identical main dishes decreased strongly at T1 (-33·9 (se 4·8) %; P<0·001). However, this effect was not found at T2 (-13·7 (se 3·2) %; P<0·001). After intervention B involving teachers, plate waste decreased at T2 (-5·5 (se 1·9) % for soup; -5·4 (se 2·4) % for identical main dishes). CONCLUSIONS: Nutrition education designed for children was more effective in the short than the medium term. Thus, this kind of intervention was not effective in reducing food waste in the medium term. In contrast, an intervention focusing on teachers revealed better results in the medium term than in the short term.

Beyond Reality: Exploring the effect of different virtual reality environments on visual assessment of cakes.

Visual assessment triggers physiological, emotional, and cognitive responses in consumer behavior. This confluence of signals can be influenced by context, which plays a crucial role in eating behavior. The strategies used to evoke scenarios that enhance ecological validity in sensory experiences have evolved in the last years to include immersive technologies and virtual reality (VR) to simulate the complexity of the real world and predict consumer preferences. This study explored VR's effect on visual liking and hedonic responses of five virtual cakes in two virtual contexts designed with advanced 3D modeling and photogrammetry techniques to ensure high realism and immersion. Although the virtual contexts themselves did not impact liking ratings, the variables "context-cake," "age," and "subjective hunger" had a significant effect on the visual liking of cakes. A Check-All-That-Apply (CATA) questionnaire showed significant differences in responses for various terms related to the intrinsic and extrinsic characteristics of the five cakes. Finally, the internal preference map separated two consumer patterns of visual liking: traditional versus innovative.

Exploring Rice Consumption Habits and Determinants of Choice, Aiming for the Development and Promotion of Rice Products with a Low Glycaemic Index.

Current consumption drivers, particularly those related to health and wellbeing, have been influencing trends for the lower consumption of cereals, particularly rice, due to their typical high glycaemic index (GIs) and consequent impacts on obesity. To satisfy this consumer concern, more food innovations that promote healthy eating habits are required. Such innovations must be consumer-oriented to succeed, understanding the dynamics of consumer habits and responding to consumer expectations. This study explored these habits, from acquisition to consumption practices, and the expectations of the European market from the perspective of the major European consumer, Portugal, to obtain insights that support the development of low glycaemic index (GI) rice products. A mixed-methods approach was applied. For the first quantitative questionnaire, 256 Portuguese rice consumers aged 18-73 years were recruited. Twenty-four individuals were selected according to their gender and rice consumption profiles for in-depth interviews. The results confirmed that rice was the main side dish for the participants and was mainly consumed at home, cooked from raw milled rice. The drivers of consumption differ according to the provisioning process stage. In the acquisition stage, participants reported benefits from the rice's dynamic market by comparing products on price, brand, and rice types. In the preparation stage, participants reported the adequacy of the recipe and occasion, while in the consumption stage, participants enhanced their sensory preferences, depending on the rice dish. Although the GI concept was unknown to half of the participants, it was perceived as interesting and positive for healthy eating. Consumers showed concern about the taste and naturalness of the product, preferring it to be as close to a homemade dish as possible. The negative perceptions we verified were interpreted to be due to a lack of knowledge about the GI concept. Therefore, awareness actions and informative campaigns are recommended to promote low-GI rice products.

Barriers and facilitators to the promotion of healthy eating lifestyles among adolescents at school: the views of school health coordinators.

This study evaluates the perceptions of teachers in charge of coordinating health education in schools: the School Health Coordinators (SHCs). It addresses the success and barriers of the development and implementation regarding the first year of healthy eating programmes in their schools. This research is based on 16 face-to-face semi-structured interviews with SHCs from Portuguese public schools offering from fifth to ninth grades. A thematic analysis was performed and themes were identified, taking into consideration similarities and differences among the participants' opinions. The results showed that the schools in this study often involved a set of separate healthy diet promotion activities with a low level of joint effort from all members of the school. Nevertheless, in Portugal, health education is based on the broad concept that school health promotion is compulsory for all schools. Two main barriers were identified in order to explain this divergence: structural and political idiosyncrasies among schools and the food environment inside and outside the schools. The results are discussed considering the wide range of factors influencing young people's eating behaviours and recommendations are made for the different agents interacting with them in order to promote appropriate eating habits.

Improving γ-Oryzanol and γ-Aminobutyric Acid Contents in Rice Beverage Amazake Produced with Brown, Milled and Germinated Rices.

Rice is an important source of γ-oryzanol (GO) and γ-aminobutyric acid (GABA), which are bioactive compounds that may benefit blood lipid and pressure control. Both GO and GABA can be improved by germination and fermentation. Fermentation with A. oryzae produces Koji, a rice-based starter for Amazake, a naturally sweet beverage. Germinated rice (brown and milled rice), were tested to improve those bioactive compounds during the fermentation process. The resulting Koji was optimised to GO and GABA through a response surface methodology; α-amylase activity and starch content were also assessed. The different rice matrix resulting from the germination largely impacted the biosynthesis of GABA, α-amylase and starch contents. Amazake, obtained by germinated rice, has increased GO and GABA contents when compared to the one obtained from milled rice (from a non-detectable value to 27.65 ± 0.23 mg/100 g for GO and from 163.95 ± 24.7 to 271.53 ± 5.7 mg/100 g for GABA). A panel of 136 Portuguese consumers tasted the beverage in a blind overall tasting test followed by an informed test, using 9-point scales. The consumer scores had a mean value of 4.67 ± 1.9 and 4.9 ± 1.8, meaning that cultural differences may play an important role with regard to liking and accepting Amazake.

Development of a Rate-All-That-Apply (RATA) ballot for sensory profiling of sea urchin (Paracentrotus lividus) gonads.

Paracentrotus lividus gonads are receiving increasing interest for their unique sensory attributes. However, the sensory profile of this highly demanded gourmet product has not yet been well described, and doing so may potentially benefit the gonads' marketability and acceptability. The main goal of this study was to build a sensory profile of sea urchin (Paracentrotus lividus) gonads, to evaluate differences between sex and harvest location. Eighty untrained panellists (regular consumers of seafood) were asked to evaluate four samples of raw sea urchin gonads (inside a sea urchin test), divided by sex and harvest location. The panellists evaluated overall liking and acceptance (Food Action Scale), followed by a Rate-All-That-Apply (RATA) ballot with a list of 22 sensory attributes divided into four dimensions: appearance (6), odour (6), texture (4) and taste (6). No significant effects of sex and harvest location were identified for liking, but a significant effect of the sex for the Food Action Rating Scale (FACT) was identified. Sensory profiling clearly separated gonads according to sex, with females being more appealing than males. Females were strongly correlated with a pleasant and intense tropical taste, as well as an overall appealing and grainy appearance and a pleasant tropical odour, while males had a slimy appearance and a milky white exudate. When compared with the Check-All-That-Apply (CATA) approach used in our previous study, the use of the RATA approach allowed to discriminate female gonads according to their origin, with those from Praia Norte being firmer, more resilient and more appealing than the ones from Carreço. This study reinforced the fact that female sea urchins tend to present an intense and pleasant tropical taste and a pleasant tropical odour, thus being more appealing to the panellists, contributing valuable information for future nutritional aquaculture studies aiming to enhance sea urchin gonads' attributes and, subsequently, their market valorisation.

Role of Visual Assessment of High-Quality Cakes in Emotional Response of Consumers.

Thinking of the present gastronomic trends is inevitable when talking about innovation in haute pastry. Launching a successful product that meets consumers' high expectations despite the rising demand for new creations is increasingly complex. For this reason, sensory analysis studies are more and more interested in studying the emotional response evoked by these products to better understand and improve user experiences. The main goal of this work was to conduct a study to analyze the emotional arousal of consumers after the visualization of five haute patisserie cakes. An online questionnaire with the EsSense Profile® scale and CATA methodology were used for data collection. The EsSense Profile® is a predefined and validated scale that measures food-related emotions, which includes 39 terms. When analyzing the emotions expressed by all the participants, 22 were statistically significant, of which 14 were classified as positive, 6 as neutral, and only 2 were negative. By analyzing the responses by gender, we observed differences in the number of elicited emotional terms: females showed significant differences between cakes for 18 emotion terms compared to 8 terms for males. The results obtained support the importance of the emotional profile to understand consumers' expectations and behavior.

Comparative Analysis between Synthetic Vitamin E and Natural Antioxidant Sources from Tomato, Carrot and Coriander in Diets for Market-Sized Dicentrarchus labrax.

Synthetic vitamin E is commonly used in aquafeeds to prevent oxidative stress in fish and delay feed and flesh oxidation during storage, but consumers' preferences tend towards natural antioxidant sources. The potential of vegetable antioxidants-rich coproducts, dried tomato (TO), carrot (CA) and coriander (CO) was compared to that of synthetic vitamin E included in diets at either a regular (CTRL; 100 mg kg-1) or reinforced dose (VITE; 500 mg kg-1). Natural antioxidants were added at 2% to the CTRL. Mixes were then extruded and dried, generating five experimental diets that were fed to European sea bass juveniles (114 g) over 12 weeks. Vitamin E and carotenoid content of extruded diets showed signs of degradation. The experimental diets had very limited effects on fish growth or body composition, immunomodulatory response, muscle and liver antioxidant potential, organoleptic properties or consumer acceptance. Altogether, experimental findings suggest that neither a heightened inclusion dose of 500 mg kg-1 of vitamin E, nor a 2% inclusion of natural antioxidants provided additional antioxidant protection, compared to fish fed diets including the regular dose of 100 mg kg-1 of vitamin E.

Biomonitoring of a population of Portuguese workers exposed to lead.

Lead is a heavy metal that has been used for many centuries and it is still used for various industrial purposes thanks to its physical and chemical characteristics. Human exposure to lead can result in a wide range of biological effects depending upon the level and duration of exposure. Despite the fact that lead has been found capable of eliciting genotoxic responses in a wide range of tests, not all studies have been conclusive. Although several experimental studies have shown that lead may modulate immune responses, data in exposed humans are still preliminary. The purpose of our study was to evaluate the genotoxic and immunotoxic effects of lead exposure in a group of 70 male workers from two Portuguese factories. The control group comprised 38 healthy males. The exposed individuals showed significantly higher levels of lead in blood and zinc protoporphyrin, and significantly lower δ-aminolevulinic acid dehydratase activity than the controls, suggesting a relatively high lead exposure. Nevertheless, the limit of 70 µg/dl for lead in blood established by the Portuguese regulation was never reached. Results of the comet assay were not modified by the exposure, but a significant increase in the mutation frequency in the exposed workers was obtained in the T-cell receptor mutation assay. Furthermore, data obtained in the analysis of the different lymphocyte subsets showed a significant decrease in %CD8+ cells and a significant increase in the %CD4+/%CD8+ ratio in exposed individuals with regard to the controls. No clear effect was observed for vitamin D receptor genetic polymorphism on the parameters evaluated. In view of our results showing mutagenic and immunotoxic effects related to lead exposure in occupational settings, it seems that the Portuguese biological exposure limit for lead needs to be revised in order to increase the safety of exposed workers.

Sensory profiling, liking and acceptance of sea urchin gonads from the North Atlantic coast of Portugal, aiming future aquaculture applications.

Sea urchin gonads are receiving increasing attention for their exclusive sensorial attributes. However, the sensory profile of this highly demanded gourmet product has not yet been well described, and it may potentially help enhancing the gonads' marketability and acceptability. The main goal of this study was to build a sensory profile of sea urchin (Paracentrotus lividus) gonads, to evaluate differences between sex, harvest location, as well as the impact of presentation on consumer acceptance. Sixty untrained panellists (regular consumers of seafood) were asked to evaluate eight samples of raw sea urchin gonads, divided by sex, harvest location and presentation (in a clear translucent glass bowl or inside a sea urchin test). The panellists evaluated overall liking and acceptance (Food Action Scale), followed by a Check-All-That-Apply (CATA) ballot with a list of 38 sensory attributes divided into four dimensions: appearance (9), odour (8), texture (7) and taste (14), launched in Sense Gest. From a three-way ANOVA, no significant effect of sex, harvest location and presentation were identified for both liking and acceptance. However, a significant interaction between presentation and sex was identified: females with gourmet presentation were rated higher than females presented in a bowl; and males presented in a bowl were favoured in relation to gourmet presentation. Sensory profiling clearly separates gonads according to sex, with females being more appealing than males that presented a milky white fluid. Gonads were also separated according to the presentation method: the white background of the bowl seemed to highlight the orange colour of females; the gourmet presentation favoured the females in relation to the males, mainly because the male gonad colour and white-colour exudate were emphasized by the background of the sea urchin test. Moreover, the gourmet presentation in both sexes was correlated with a fresh, tropical and pleasant odour. This study concluded that sea urchin with an orange gonad and a sweet, fresh and tropical flavour is preferable, which will allow future nutritional research efforts to be focused on the enhancement of these gonad attributes.

Factors influencing food waste during lunch of fourth-grade school children.

This study aims to explore the factors that influence plate waste at lunches served in primary schools. Data was collected for all fourth-grade children attending 21 primary schools from the city of Porto (Portugal) (n = 463). Plate waste was evaluated by the weighing method and factors influencing plate waste were collected by observation of menu and canteen characteristics and through the application of a questionnaire to children aiming to evaluate factors related to preferences and dietary patterns. Logistic regression was performed to identify predictors of plate waste. It was observed that fish menus and composed dishes showed a higher tendency for increased plate waste. However, this effect was not observed when adjusted for other variables. Soups without pulses and blended soups were less likely to be discarded by children. The presence of the teacher during meals and the possibility for children to leave the canteen whenever they wish, protected both the main dish and the soup from being wasted. A higher number of children in the canteen was associated with increased soup waste. As expected, children more pleased with the sensory characteristics of the main dish and soup were less likely to waste food. Children who consumed high-saturated fat content mid-morning snacks were more likely to waste soup. The main factors associated with plate waste were related to the presence of teachers during the mealtime, school meal policies and the meals' sensory characteristics. Additionally, soup waste was determined by its composition, mid-morning snacks and the number of children in the canteen.

Exploiting the bioactive properties of γ-oryzanol from bran of different exotic rice varieties.

The rice industry is one of the most significant food industries since rice is a widely consumed cereal in the world. As a result of this substantial production, the rice industry has a significant amount of side streams, including bran, representing millions of tons of raw materials mainly designated to animal feed. Rice bran is a rich source of γ-oryzanol, a bioactive compound with substantial health benefits. In this perspective, different bran rice samples from distinct germplasm origins (Philippines, Italy and Portugal) were studied for their γ-oryzanol content by HPLC-PDA, cytotoxicity in four human tumour cell lines, hepatotoxicity in a normal cell line and for their antimicrobial effects on different bacterial and fungal strains. The Ballatinao sample presented the strongest activity against all the tumour cell lines, and was also the sample showing the highest amount of γ-oryzanol, suggesting its contribution to the exhibited cytotoxic properties. Regarding the antimicrobial activity, the tested samples were able to inhibit the majority of bacterial and fungal strains, with the Portuguese Ceres sample being the one presenting the highest bacterial inhibition and the Maluit and Dinorado samples, the highest fungal inhibition. Overall, the results show that rice bran extracts may be considered as potential candidates for antimicrobial agents when incorporated into food matrices.

Consumer-Driven Improvement of Maize Bread Formulations with Legume Fortification.

The fortification of maize bread with legume flour was explored in order to increase the protein content of the traditional Portuguese bread 'broa', comprised of more than 50% maize flour. The optimization of legume incorporation (pea, chickpea, faba bean, lentil), considering the influence of different maize flours (traditional-white, traditional-yellow, hybrid-white, hybrid-yellow), on consumer liking and sensory profiling of 'broa' was studied. A panel of 60 naïve tasters evaluated twenty different breads, divided in four sets for each legume flour fortification, each set including four breads with varying maize flour and a control (no legume). Tasters evaluated overall liking and the sensory profile through a check-all-that-apply ballot. Crude protein and water content were also analyzed. There were no significant differences in overall liking between the different types of legumes and maize. The incorporation of chickpea flour yields a sensory profile that most closely resembles the control. The protein content increased, on average, 21% in 'broa', with legume flours having the highest value obtained with faba bean incorporation (29% increase). Thus, incorporation of legume flours appears to be an interesting strategy to increase bread protein content, with no significant impact on consumer liking and the 'broa' bread sensory profile.

Sugar reduction in fruit nectars: Impact on consumers' sensory and hedonic perception.

Sugar sweetened beverages are one of the main sources of added sugar in the diet. Therefore, sugar reduction in these products could contribute to the prevention of various negative health conditions, such as obesity, diabetes and cardiovascular diseases. In this context, the present work aimed to study consumer sensory and hedonic perception towards sugar reduction in fruit nectars. Five sequential difference thresholds for added sugar in three fruit nectars (passion fruit, orange/passion fruit and orange/pomegranate) were determined based on consumer perception. In each test, difference thresholds were estimated using survival analysis based on the responses of 50 consumers to six paired-comparison tests. Each pair was composed of two samples, a control nectar and a sample that was reduced in added sugar from the control. Consumers were asked to try each of the samples in each pair and to indicate which was sweeter. Then, consumers' sensory and hedonic perception of nectar samples was evaluated for each nectar using a 9-point hedonic scale and a check-all-that-apply question. Difference thresholds were estimated in 4.20%-8.14% of the added sugar concentration of the nectars. No significant differences in overall liking were detected for fruit nectars with 20% sugar reduction. However, large heterogeneity in consumer hedonic reaction towards sugar reduction was found, which should be taken into account in the design of sugar reduction programs. Consumer hedonic reaction towards sugar reduction was product dependent. Results from the present work reinforce the idea that gradual sugar reduction in sugar sweetened beverages is a feasible strategy that could contribute to reduce the sugar intake of the population.

Evaluation of the joint effect of the incorporation of mechanically deboned meat and grape extract on the formulation of chicken nuggets.

The proximate composition, instrumental and perceived appearance of chicken nuggets formulated with varying contents of mechanically deboned chicken meat and varying concentrations of grape pomace extract were evaluated, with the choice of formulations following a central composite design. Significant differences (P < 0.05) in fat content were mainly associated to the extent of mechanically deboned chicken meat incorporation. Colour variables ( CIE a* and b*, and Whiteness index) varied significantly (P < 0.05), with redness (a*) being the variable most influenced by the incorporation of mechanically deboned chicken meat. Whiteness index decreased with added mechanically deboned chicken meat and grape pomace extract. Response surface was applied to identify formulations with higher acceptance scores. Correspondence analysis of open-ended comments complemented the information obtained from overall acceptance, adding valuable descriptive attributes of nugget samples. Thus, addition of grape pomace extract up to 120 mg/kg and mechanically deboned chicken meat up to 15 g/100 g did not adversely affect the perceived appearance of chicken nuggets. Mechanically deboned chicken meat and grape pomace extract can be successfully used for the elaboration of novel products, for different market segments, with healthy connotations highlighted by antioxidant properties retained by the grape pomace extract.

Evaluation of genotoxicity in a group of workers from a petroleum refinery aromatics plant.

Petroleum refinery workers are potentially exposed to a wide range of petroleum-derived hydrocarbons and chemical substances used in the manufacturing of petroleum derivatives. Benzene, toluene and xylene (BTX) are produced by distillation in the aromatics units and used as raw materials for petrol and petrochemical products. The aim of this study was to evaluate the genotoxic effects of occupational exposure to BTX in a petroleum refinery in the North of Portugal. The exposed group consisted of 48 workers from the aromatics plant and the control group consisted of 30 persons matched for various confounding factors. Chromosome aberrations (CA), micronuclei (MN), and DNA damage (evaluated by means of the comet assay) were measured in peripheral blood leukocytes. t,t-Muconic acid (t,t-MA), hippuric acid (HA) and methylhippuric acid (MHA) concentrations were measured in urine samples collected at the end of the workshift. The results suggest that occupational exposure to toluene and xylene is very low. A statistically significant increase in t,t-MA excretion was found in the exposed group although t,t-MA levels were found to be lower than the biological exposure index (BEI). Significant increases were found for CA, MN and comet tail length (TL) in the exposed group (p<0.05). No association was found between tobacco smoking and the effect biomarkers analysed. A positive association was found between CA and MN with age in the control group (p<0.05).

Modelling the influence of time and temperature on the respiration rate of fresh oyster mushrooms.

The respiration rate of mushrooms is an important indicator of postharvest senescence. Storage temperature plays a major role in their rate of respiration and, therefore, in their postharvest life. In this context, reliable predictions of respiration rates are critical for the development of modified atmosphere packaging that ultimately will maximise the quality of the product to be presented to consumers. This work was undertaken to study the influence of storage time and temperature on the respiration rate of oyster mushrooms. For that purpose, oyster mushrooms were stored at constant temperatures of 2, 6, 10, 14 and 18 ℃ under ambient atmosphere. Respiration rate data were measured with 8-h intervals up to 240 h. A decrease of respiration rate was found after cutting of the carpophores. Therefore, time effect on respiration rate was modelled using a first-order decay model. The results also show the positive influence of temperature on mushroom respiration rate. The model explaining the effect of time on oyster mushroom's respiration rate included the temperature dependence according to the Arrhenius equation, and the inclusion of a parameter describing the decrease of the respiration rate, from the initial time until equilibrium. These yielded an overall model that fitted well to the experimental data. Moreover, results show that the overall model is useful to predict respiration rate of oyster mushrooms at different temperatures and times, using the initial respiration rate of mushrooms. Furthermore, predictive modelling can be relevant for the choice of an appropriate packaging system for fresh oyster mushrooms.

Determination of plate waste in primary school lunches by weighing and visual estimation methods: a validation study.

The aim of this study was to validate the visual estimation method for aggregated plate waste of main dish at Portuguese primary school canteens. For this purpose plate waste at school lunch was measured for 505 individual servings, using weighing individual servings and plate waste and visual estimation method by a 6-point scale, as developed by Comstock et al. (1981). A high variability of initial serving weights was found with serving sizes ranging from 88.9 to 283.3g and with a coefficient of variation ranging from 5.5% to 24.7%. Mean plate waste was 27.5% according to the weighing method. There was a significant bias in the conversion of the visual waste estimations to actual waste, being overestimated by an average of 8.0 g (ranging from -12.9 g to 41.4 g). According to Bland and Altman plot, the mean difference between methods was of 8.0 g and the amplitude interval was 102.6g. The study showed that the visual estimation method is not as accurate as the weighing method in assessing nonselective aggregated plate waste at primary school canteens. Our findings are thus very important on considering plate waste assessment, since the wide variation on initial servings introduces a relevant bias when considering standard portions or a random sample of initial servings. Although, greater convenience, time-saving and the possibility to monitor plate waste of large groups, make the visual estimation method an important method to assess plate waste at school canteens, these results highlighted the need of portions standardization and control of initial servings to allow for its use.