155 research outputs found

    Nir Spectral Techniques and Chemometrics Applied to Food Processing

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    Tesis por compendio[ES] Las técnicas rápidas, no destructivas y libres de químicos tienen una demanda creciente en muchos campos de la industria. Las técnicas de espectroscopia de infrarrojo cercano (NIRS) y imágenes hiperespectrales NIR (NIR-HSI) han mostrado un gran potencial para determinar los parámetros de calidad de los alimentos, autenticar productos alimenticios, detectar el fraude, entre otras. En la NIRS, las medidas se toman en puntos específicos, detectando solo una pequeña porción; en la NIR-HSI, la información espectral y espacial se combinan, lo que la convierte en una opción adecuada para muchos productos alimenticios, ya que son matrices muy heterogéneas. Por lo tanto, este estudio tuvo como objetivo revisar la aplicación de NIRS (dispersivos), NIR de Transformada de Fourier (FT) y HSI en la evaluación de los parámetros de calidad de harina de trigo y productos a base de trigo, así como para la autenticación y determinación de la composición de estos productos. Además, este trabajo tuvo como objetivo identificar y clasificar diferentes tipos de muestras de fibra agregadas a la semolina y pasta producidas por estas formulaciones, y monitorear el proceso de cocción de esta pasta enriquecida en fibra mediante técnicas espectrales. Además, se objetivó aplicar HSI a otro producto en polvo, por lo que se cuantificó el contenido de pectina en las cáscaras de naranja. Primero, se adquirieron espectros NIR para comparar la precisión en la clasificación de muestras enriquecidas con fibra, para cuantificar la cantidad de estas fibras y verificar su distribución en muestras de semolina. Para la clasificación se utilizaron el Análisis de Componentes Principales (PCA) y el Soft Independent Modelling of Class Analogy (SIMCA). Los modelos de regresión de mínimos cuadrados parciales (PLSR) aplicados a espectros NIR-HSI mostraron R²P entre 0,85 y 0,98 y RMSEP entre 0,5 y 1, y los modelos se utilizaron para construir los mapas químicos para verificar la distribución de fibra en las superficies de las muestras. Además, se probó el NIR-HSI junto con Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) para investigar la capacidad de evaluación, resolución y cuantificación de la distribución de fibra en la pasta. Los resultados mostraron R²P entre 0.28 y 0.89,% de falta de ajuste (LOF) <6%, varianza explicada sobre 99% y similitud entre espectros puros y recuperados sobre 96% y 98%. Además, se probó VIS/NIR-HSI en el modo de transmisión como una alternativa objetiva para la clasificación de muestras de pasta según el tiempo de cocción. El análisis discriminante lineal (LDA) mostró valores de sensibilidad y especificidad entre 0,14-1,00 y 0,51-1,00, respectivamente, y una tasa de ausencia de error (NER) superior a 0,62. El análisis discriminante de mínimos cuadrados parciales (PLSDA) mostró valores de sensibilidad y especificidad entre 0,67-1,00 y 0,10-1,00, respectivamente, y NER superiores a 0,80. Los resultados de este trabajo mostraron que la técnica NIR-HSI se puede utilizar para la identificación y cuantificación de la fibra agregada a la semolina. Además, NIR-HSI y MCR-ALS pueden identificar la fibra en la pasta. La HSI en el modo de transmisión demostró ser una técnica adecuada como alternativa objetiva para la clasificación de muestras de pasta según el tiempo de cocción como una forma de automatizar la determinación de los atributos de la pasta. La determinación del contenido de pectina en cáscaras de naranja se investigó usando NIR-HSI. LDA mostró mejores resultados de discriminación considerando tres grupos: bajo (0-5%), intermedio (10-40%) y alto (50-100%) contenido. Los modelos PLSR basados en espectros completos mostraron mayor precisión (R2> 0,93, RMSEP entre 6,50 y 9,16% de pectina) que los basados en pocas longitudes de onda seleccionadas (R2 entre 0,92 y 0,94, RMSEP entre 8,03 y 9,73% de pectina). Los resultados demuestran el potencial de NIR-HSI para cuantificar el contenido de pectina en las cáscaras de naranja, proporcionando una técnica valiosa para los productores de naranja y las industrias de procesamiento.[CA] Les tècniques ràpides, no destructives i lliures de químics tenen una demanda creixent en molts camps de la indústria. Les tècniques d'espectroscopia d'infraroig proper (NIRS) i d'imatges hiperespectrals NIR (NIR-HSI) han demostrat tindre un gran potencial per a determinar paràmetres de qualitat d'aliments, autenticar productes alimentaris, detectar frau entre altres aplicacions. Mentre que en la NIRS proper les mesures es prenen en punts específics de la mostra i es detecta una porció menuda, en la HSI es combina informació espectral i espacial de tal manera que és una opció adient per a molts tipus de productes alimentaris, ja que són matrius molt heterogènies. Per tant, este estudi va tindre com objectiu revisar tota l'aplicació de NIRS (dispersius), NIR de Transformada de Fourier (FT) i HSI en l'avaluació dels paràmetres de qualitat de la farina de blat i els productes a base de blat, així com per a l'autenticació i determinació de la composició d'estos productes. A més a més, este estudi va tindre com objectiu identificar i classificar diferents tipus de mostres de fibra afegides a la semolina i pasta produïdes per formulació de fibra i semolina, i monitorar mitjançant tècniques espectrals el procés de cocció d'aquesta pasta enriquida amb fibra. A més, este treball va tindre com objectiu aplicar HSI a un altre producte en pols, de tal manera que es va quantificar el contingut de pectina en les corfes de taronja. Primer, es van adquirir espectres NIR per comparar la precisió en la classificació de mostres enriquides amb fibra, per quantificar estes fibres i verificar la seua distribució en mostres de sèmola. Per a la classificació es van emprar l'Anàlisi de Components Principals (PCA) i el SIMCA (Soft Independent Modelling of Class Analogy). Els models de regressió de mínims quadrats parcials (PLSR) aplicats a espectres NIR-HSI mostraren R²P entre 0,85 i 0,98 i RMSEP entre 0,5 i 1% de contingut de fibra, i els models s'utilitzaren per construir els mapes químics per verificar la distribució de fibra en les superficies de les mostres. Així mateix, es va provar NIR-HSI amb Multivariate Curve Resolution-Alternating Least Square (MCR-ALS) per a investigar la capacitat d'avaluació, resolució i quantificació de la distribució de fibra en la pasta enriquida. Els resultats mostraren un R²P entre 0,28 i 0,89%, lack of fit (LOF) 0,93, RMSEP entre 6,50 i 9,16% de pectina) que els basats en longituds d’ona seleccionades (R2 entre 0,92 i 0,94, RMSEP entre 8,03 i 9,73% de pectina). Els resultats demostren el potencial de NIR-HSI per a quantificar el contingut de pectina en corfa de taronja i proporcionen una tècnica valuosa per als productors de taronja i les indústries de processament.[EN] Fast, non-destructive and chemical-free techniques are in increasing demand in many fields of the industry. Near-infrared spectroscopy (NIRS) and NIR hyperspectral imaging (NIR-HSI) techniques have shown great potential in determining food quality parameters, authenticating food products, detecting food fraud, among many other applications. While in near infrared spectroscopy, the measurements are taken at specific points on the sample, detecting only a small portion; in hyperspectral imaging, spectral and spatial information are combined, making it a suitable choice for many food products, since they are very heterogeneous matrices. Therefore, this study aimed to review all the application of (dispersive) NIRS, Fourier Transform (FT) NIR, and HSI in assessing wheat flour and wheat-based products quality parameters, as well for the authentication and determination of composition of these products. Moreover, this work aimed to identify and classify different types of fibre samples added to the semolina and pasta produced by semolina-fibre formulations, and to monitor the cooking process of this fibre-enriched pasta by spectral techniques. In addition, this work had the aim of applying HSI to other powdered product, so the pectin content in orange peels was quantified. First, NIR spectra were acquired to compare the accuracy in the classification of fibre-enriched samples, to quantify the amount of these fibres and verify their distribution on semolina samples. Principal Component Analysis (PCA) and Soft Independent Modelling of Class Analogy (SIMCA) were used for classification. Partial Least Squares Regression (PLSR) models applied to NIR-HSI spectra showed R2P between 0.85 and 0.98, and RMSEP between 0.5 and 1% of fibre content, and the models were used to construct the chemical maps to check the fibre distribution on the samples surface. Moreover, NIR-HSI together with Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS), was tested to investigate the ability for the evaluation, resolution and quantification of fibre distribution in enriched pasta. Results showed coefficient of determination of validation (R²V) between 0.28 and 0.89, % of lack of fit (LOF) 0.93, RMSEP between 6.50 and 9.16% of pectin) than those based on few selected wavelengths (R² between 0.92 and 0.94, RMSEP between 8.03 and 9.73%). The results demonstrate the potential of NIR-HSI to quantify pectin content in orange peels, providing a valuable technique for orange producers and processing industries.This work was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior- Brasil (CAPES) [Finance Code 001]; São Paulo Research Foundation (FAPESP) [grant numbers 2015/24351-2, 2017/17628-3, 2019/06842- 0]; and by projects AEI PID2019-107347RR-C31 and PID2019-107347RR-C32, and the European Union through the European Regional Development Fund (ERDF) of the Generalitat Valenciana 2014-2020. The authors would like to thank Nutrassim Food Ingredients company for the donation of the fibre samples, the support provided by Enrique Aguilar María, Carlos Alberto Velasquez Hernández, Diego Hernández Catalán, Carlos Ruiz Catalá and Andrés Estuardo Prieto López during system installation, experimental analysis and data acquisition.Teixeira Badaró, A. (2021). Nir Spectral Techniques and Chemometrics Applied to Food Processing [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/178758Compendi

    Optimising beverages for satiety: the role of sensory characteristics, expectations and nutrient content

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    Regularly consuming caloric beverages has been linked to obesity and weight gain and evidence suggests this is because beverages have a weak impact on satiety responses (behavioural and physiological). Using a series of experimental studies this thesis explored the cognitive and sensory features of caloric beverages that might enhance the anticipated and actual satiating power of their nutrients. Paper one characterised the sensory characteristics associated with expectations of hunger, fullness and thirst, finding that food and beverage products anticipated to be creamier and thicker were expected to be more satiating and less thirst-quenching. Paper two established that people can perceive subtle changes in beverage viscosity and manipulating thick and creamy textural cues strongly influenced the expectation that a beverage would be filling and supress hunger after consumption. This was extended in paper three, which reported evidence suggesting that a sensorially enhanced beverage is selected and consumed in smaller portions. Papers four and five investigated the satiating power of a caloric beverage consumed with satiety-relevant cognitive and sensory information. Paper four reported tentative evidence that a labelled satiety message influenced the satiating effect of caloric beverages when combined with thick and creamy sensory cues. Participants in Paper five reported greater satiety responses to a covert manipulation of beverage energy when consumed as a ‘snack’ rather than a drink. However, consuming the same beverage in a subtly thicker sensory context (without extra information) generated the largest satiety response to the different nutrient loads, perhaps because textural characteristics are the most reliable cue for nutrients. Overall these studies suggest that caloric beverages may generate weak satiety responses because their nutrient-generated effects are not expected. Encouraging people to consider caloric beverages as a snack, or adding in nutrient-relevant sensory characteristics, may both help consumers regulate energy intake when consuming these products

    More Than Just A Diet: An Inquiry Into Veganism

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    BACKGROUND: The vegan diet has gained momentum in recent years, with more people transitioning to the diet, whether for health or more ethically based reasons. The vegan diet, often characterized as very restrictive, is associated with health benefits but raises concerns. Controversy regarding the diet exists within the public sphere, with those actively supporting and advocating for it, and others questioning its purpose and proposed benefits, even disparaging its existence, perhaps because of a lack of knowledge about the diet. OBJECTIVE: This study aimed to provide a fuller picture of the vegan diet, encompassing both the nutrition and health of the vegan diet as well as related ethical beliefs by studying scientific and popular literature in tandem. Furthermore, the study aimed to provide an insider’s perspective of the vegan diet as a means of combating stereotypes and making the diet more relatable/understandable to those who are not vegan. By combining all three sources, the project aims to educate the public regarding a diet and lifestyle that is often perceived, at least partially, in a negative manner. METHODS: The research was conducted in two parts – literature review and interview study. A literature review of both the scientific and the popular literature was conducted and reviewed from August to November. Pubmed database was used to research the scientific findings while food blogs, vegan websites, and newspaper articles comprised the popular literature. The interview study involved semi-structured, one-time, in-person private interviews conducted during February and March. Twenty vegans (10 students from the University of Pennsylvania and 10 Philadelphia residents) were interviewed and questions targeted personal history of veganism, related health beliefs, factors influencing the decision to become vegan, and diet composition. Once all data was obtained, it was analyzed in tandem. RESULTS: Findings suggest that a well-rounded vegan diet is healthy and such is evidenced by the variety of whole foods and increased vegetable and fruit intake. Health benefits include a decrease in cholesterol, lipid levels, blood pressure, weight, and a reduced risk for a variety of diseases including obesity, diabetes, cardiovascular disease, and cancer. Despite the benefits, health concerns do exist, especially in regard nutrient deficiencies, without a well-planned and varied diet. Nutrient concerns include calcium, vitamin D, iron, and particularly vitamin B-12 for which supplements should be taken. The nature of the interviews conducted for this paper was such that a comprehensive but diverse collection of information was obtained, precisely because the interviewees have chosen the vegan diet for a multitude of reasons, and approach their diet and lifestyle in varied ways. However, there are some commonalities that were revealed. Results of the interview studies demonstrate that about half of the vegans are potentially at risk for vitamin D deficiency because most are taking neither vitamin D supplements nor a multivitamin. Comparing the scientific literature with the interview results reveal that most of the vegans include working out within their daily routines, such that they place emphasis upon physical fitness, suggesting that the vegan lifestyle has benefits beyond merely nutritional. Finally, comparing popular literature to the information gleaned through the interviews conducted establishes that many of the stereotypes regarding the vegan diet are unfounded. CONCLUSIONS: The vegan diet is one that is chosen by individuals for various reasons, including health and/or ethical reasons. While many health benefits exist, it is essential for those who are vegan or are planning to become vegan to be educated about potential nutrient deficiencies to prevent adverse outcomes. In addition, it is evident that the vegan diet is much more than a diet itself, but has developed into a lifestyle, often associated with animal rights and environmental advocacy as well as a greater concern for physical activity and mindfulness. Further research begs the question of whether the health benefits associated with the diet are solely attributable to the diet or in conjunction with a greater physical activity level and mindful living. With regard to providing an accurate picture of veganism in the popular literature, it is essential to combat negative unsubstantiated stereotypes and myths by providing vegans with unbiased voice with which to share their own stories and beliefs. Lastly, the popularity of the vegan diet and the question of whether it is nutritionally sound, raise issues of anthropologic significance. Specifically, it prompts consideration of whether our ancestral diet was vegetarian in nature, or depended upon meat for evolutionary progress. Moreover, this study demonstrates that the human diet has changed over time, such that our dietary needs, choices and preferences are inherently reflective of cultural and nutritional anthropology

    Exploring preferential food selection: a cross-cultural study between Chinese and Malay undergraduates in a private university

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    Previous studies and cross-sectional surveys conducted in Malaysia have shown that the prevalence of obesity, diabetes and other non-communicable diseases (NCDs) are associated with poor diet practices. Overeating is contributing to the increasing prevalence of obesity and other NCDs among Malaysians. This study aims to investigate how environmental influences might impact food preferences between Malay and Chinese. Past research shows that ethnicity is related to differences in food-related beliefs, preferences and overall eating behaviour. To investigate how environmental factors might influence food preferences, a series of experiments were conducted using psychological paradigms. First, food consumption patterns using a Food Frequency Questionnaire (Chapter 2) between the two groups were compared. It was found that Malay participants consumed more spicy and savoury foods, and larger portions of both artificially and naturally sweet foods, such as fruits. Overall findings of the FFQ showed that Malay participants consume a higher level of energy intake compared to the Chinese participants, which is reflective of existing literature in Malaysia. Additionally, Malay participants showed a preference for wheat-based foods other than rice- which is staple food in traditional Malay cuisine. In contrast, Chinese participants showed a higher preference for traditional Chinese cuisine for everyday meals such as noodles and porridge. Preferential food selection was examined using a 2AFC method (Chapter 3). Malay participants selected spicy foods more than Chinese participants, and both groups made more preferential selections of savoury foods than they did for spicy foods. Malay participants made the most selections for sweet foods, whereas the Chinese participants chose savoury foods the most. Spicy foods were the least preferred among the Chinese participants, whereas the control food items (e.g. raw vegetables and fruits) were the least preferred among Malays. To understand whether selections made on a 2AFC task are representations of actual preferences; a categorization and ratings task was given to assess participants’ recognition of spicy, savoury, and sweet foods (Chapter 4). Results showed that Malay participants had significantly more errors in categorizing the savoury foods than Chinese participants, while the Chinese participants made significantly more errors in categorizing spicy foods than the Malay participants. Both groups attributed highest ratings of palatability to spicy foods, followed by sweet foods and rated control foods the lowest. The Chinese participants found spicy foods to be higher in flavour compared to the other categories of food. It is proposed that although the Chinese participants might not consume spicy foods on a regular basis, they provided higher ratings of palatability. The effects of semantic priming on categorising different categories of foods flavours between the groups was examined in Chapter 5. It was predicted that the presence of a prime (visual imagery) would interfere with participants’ abilities in characterising target words effectively depending on what category the prime represented. Malay participants had higher errors than Chinese participants in processing target words from spicy, sweet, and control categories although this difference was not significant. Both groups had difficulties in characterising spicy and savoury target words when the prime presented were spicy and savoury food stimulus. The final experiment explored the role memory and familiarization in food recognition abilities across the two groups. Certain types of dishes might be more “salient objects” for one group rather than the other and this could influence food preferences (Chapter 6). Results showed a higher average consumption quotient for spicy, savoury and sweet foods on the R-FFQ among the Malay participants. Malay participants were not more susceptible in discriminating repetitions of spicy and sweet food stimuli more than the savoury and control food stimuli. Although Malay participants exhibited the lowest d’ scores in recognition for the spicy food items, scores were not significantly different from scores in recognizing the other food categories. Chinese participants showed the highest accuracy in recognition for control food items, and no relationship between familiarity and recognition of the savoury food items. We were unable to establish a connection between familiar foods and performance on the recognition task. Cumulatively, the overall findings from this entire investigation raises questions about measures which can effectively measure food selection. For future studies, we hope to employ more indirect, discreet measures in assessing preferential food selection among Malaysians. Overall, the findings show that both groups show a slight predisposition towards flavour components present in their traditional cuisines, but more research needs to be carried out to understand this further

    Qualitative and Nutritional Improvement of Cereal-Based Foods and Beverages

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    Increased consumer awareness of the effects of food in preventing nutrient-related diseases and maintaining physical and mental well-being has made nutritional improvement an important goal for the food and beverage industry, including the cereal sector. The Book “Qualitative and Nutritional Improvement of Cereal-Based Foods and Beverages” collects research articles aimed at exploring innovative ways to improve cereal-based foods and beverages; an old—if not ancient—group of products which are still on our table every day. The main directions of research aimed at nutritional improvement have to face either excess or deficiency in the diet. To this end, different strategies may be adopted, such as the reformulation of products, the introduction of functional ingredients, and the application of biotechnologies to increase the bioavailability of bioactive compounds. These interventions, however, can alter the physico-chemical and sensory properties of final products, making it necessary to achieve a balance between nutritional and quality modification. This book offers readers information on innovative ways to improve cereal-based foods and beverages, useful for researchers and for industry operators

    Sensory Analysis and Consumer Research in New Product Development

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    Sensory analysis and consumer research are relevant tools in innovation andnew product development, from design to commercialization. This Special Issuehas collected 13 valuable scientific contributions, including 1 review, 12 originalresearch articles and an editorial. The SI provides an interesting outlookand better understanding of sensorial analysis with the different techniques andconsumer research on new product development. Important practical applicationshave been reported on the development of different novel, functional andenhanced products (meat, fish, biscuits, yogurt, porridge, hybrid meat, molecularproducts, etc.), which helps increase knowledge in this field. This SI isvery useful for both present and future uses for the different players involved inthis kind of product development (industry, companies, researchers, scientists,marketing, merchandising, consumers, etc.)

    Novel Texture-based Probabilistic Object Recognition and Tracking Techniques for Food Intake Analysis and Traffic Monitoring

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    More complex image understanding algorithms are increasingly practical in a host of emerging applications. Object tracking has value in surveillance and data farming; and object recognition has applications in surveillance, data management, and industrial automation. In this work we introduce an object recognition application in automated nutritional intake analysis and a tracking application intended for surveillance in low quality videos. Automated food recognition is useful for personal health applications as well as nutritional studies used to improve public health or inform lawmakers. We introduce a complete, end-to-end system for automated food intake measurement. Images taken by a digital camera are analyzed, plates and food are located, food type is determined by neural network, distance and angle of food is determined and 3D volume estimated, the results are cross referenced with a nutritional database, and before and after meal photos are compared to determine nutritional intake. We compare against contemporary systems and provide detailed experimental results of our system\u27s performance. Our tracking systems consider the problem of car and human tracking on potentially very low quality surveillance videos, from fixed camera or high flying \acrfull{uav}. Our agile framework switches among different simple trackers to find the most applicable tracker based on the object and video properties. Our MAPTrack is an evolution of the agile tracker that uses soft switching to optimize between multiple pertinent trackers, and tracks objects based on motion, appearance, and positional data. In both cases we provide comparisons against trackers intended for similar applications i.e., trackers that stress robustness in bad conditions, with competitive results
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