Shelf Life and Functional Quality of Almond Bagasse Powders as Influenced by Dehydration and Storing Conditions.

Almond bagasse resulting after the production of almond-based drinks represents a promising by-product with potential for use as a functional ingredient. To facilitate its utilization, the stability of this material can be achieved through dehydration processes such as hot air drying or freeze-drying. Nevertheless, owing to its high fat content, almond bagasse is prone to lipid oxidation, which could result in undesirable quality. Therefore, the objective of this work was to assess the impact of dehydration (by hot air drying at 60 and 70 °C and by freeze-drying) and storage (at room temperature and in accelerated conditions) on the functional quality and stability of almond bagasse powder. Throughout the dehydration process, it was observed that antioxidant compounds were preserved without significant differences among dehydration treatments. These compounds increased over the storage period, especially in the samples treated with hot air. Regarding antiradical capacity, the hot-air-dried samples showed higher values than the freeze-dried ones, although in all cases, it increased during storage. For total phenols in samples air-dried at 70 °C, increases of more than 50% were observed. The acidity and peroxide index were increased in the extended storage period, although they did not reach critical values. Samples stored for 180 days showed peroxide values ranging from 10 to 12.8 meq O2/kg dry matter for samples stored at room temperature and from 14.7 to 23 meq O2/kg dry matter for samples subjected to accelerated storage.

Antioxidant activity of rosemary extract, acerola extract and a mixture of tocopherols in sausage during storage at 8 °C.

Sausage is an emulsified meat product that, due to its composition, undergoes physicochemical changes during its shelf life, which makes the use of additives for its conservation necessary. The goal of the present study was to evaluate the antioxidant capacity of rosemary extract, acerola extract, and a mixture of tocopherols applied to industrialized sausages during storage at 8 °C. The antioxidant activity (IC50) in vitro showed values of 0.043, 0.489, 0.494, and 0.509 mg/mL for sodium erythorbate, rosemary extract, acerola extract, and a mixture of tocopherols, respectively. Formulations of sausage obtained in industrial installations were evaluated in terms of physicochemical, microbiological, and sensorial analyses. The pH and acidity values were stable during 23 days of storage. Treatments 1 and 3 with acerola extract and a mixture of tocopherols associated with sodium erythorbate showed the best results against lipid oxidation (TBARs), respectively. The hydroperoxides were only found after the 12th day of storage, consequently reducing the formation of malondialdehyde. The treatments with natural antioxidants showed an antimicrobial effect for the group of mesophilic bacteria; their results did not exceed 4 log10 CFU/g, while the control reached 5 log10 CFU/g on the 23rd day of storage. In regard to other microorganisms evaluated, no significant differences were found between treatments with natural antioxidants. Thus, the natural extracts evaluated in association with sodium erythorbate contributed to the antioxidant action for the application on an industrial scale, as they improved the sausage characteristics after 23 days of storage at 8 °C. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05815-y.

FT-MIR-ATR Associated with Chemometrics Methods: A Preliminary Analysis of Deterioration State of Brazil Nut Oil.

Brazil nut oil is highly valued in the food, cosmetic, chemical, and pharmaceutical industries, as well as other sectors of the economy. This work aims to use the Fourier transform infrared (FTIR) technique associated with partial least squares regression (PLSR) and principal component analysis (PCA) to demonstrate that these methods can be used in a prior and rapid analysis in quality control. Natural oils were extracted and stored for chemical analysis. PCA presented two groups regarding the state of degradation, subdivided into super-degraded and partially degraded groups in 99.88% of the explained variance. The applied PLS reported an acidity index (AI) prediction model with root mean square error of calibration (RMSEC) = 1.8564, root mean square error of cross-validation (REMSECV) = 4.2641, root mean square error of prediction (RMSEP) = 2.1491, R2cal (calibration correlation coefficient) equal to 0.9679, R2val (validation correlation coefficient) equal to 0.8474, and R2pred (prediction correlation coefficient) equal to 0, 8468. The peroxide index (PI) prediction model showed RMSEC = 0.0005, REMSECV = 0.0016, RMSEP = 0.00079, calibration R2 equal to 0.9670, cross-validation R2 equal to 0.7149, and R2 of prediction equal to 0.9099. The physical-chemical analyses identified that five samples fit in the food sector and the others fit in other sectors of the economy. In this way, the preliminary monitoring of the state of degradation was reported, and the prediction models of the peroxide and acidity indexes in Brazil nut oil for quality control were determined.

Field-Deployable Determinations of Peroxide Index and Total Phenolic Content in Olive Oil Using a Promising Portable Sensor System.

Useful information about the oxidative stability of a virgin olive oil in terms of oxidation products and antioxidant compounds can be obtained by analyzing the peroxide index (PI) and total phenolic content (TPC), respectively. These quality parameters are usually determined in a chemical laboratory using expensive equipment, toxic solvents, and well-trained personnel. This paper presents a novel portable sensor system for in the field and rapid determination of PI and TPC that is particularly suited in the case of small production environments that cannot afford an internal laboratory for quality control analysis. The system is small, can be powered by both USB ports and batteries, is easy to operate, and integrates a Bluetooth module for wireless data transmission. It estimates the PI and TPC in olive oil from the measurement of the optical attenuation of an emulsion between a reagent and the sample under test. The system has been tested on a set of 12 olive oil samples (eight for calibration and four for validation), and the results have shown how the considered parameters can be estimated with good accuracy. The maximum deviation from the results obtained with the reference analytical techniques is 4.7 meq O2/kg in the case of PI and 45.3 ppm in the case of TPC for the calibration set, while it is 14.8 meq O2/kg in the case of PI and 55 ppm in the case of TPC for the validation set.

Application of Poultry Gelatin to Enhance the Physicochemical, Mechanical, and Rheological Properties of Fish Gelatin as Alternative Mammalian Gelatin Films for Food Packaging.

This study aimed to describe the properties of cold water fish gelatin (FG) blended with poultry gelatin (PG) for a production of a sachet containing olive oil. To find a desirable film, the different ratio of FG-PG-based films were characterized in terms of mechanical properties. As the proportion of PG in PG-FG-based increased, the tensile strength and Young's modulus were increased, and the elongation at break and heat seal strength of the films were decreased. The 50-50 film had favorable characteristics to use as a sachet. The amount of acid index and peroxide of the oil stored in the sachets after 14 days showed that there is a significant difference (p < 0.05) between the films. The barrier properties of the films including the water vapor permeability and oxygen permeability of films were increased from 1.21 to 4.95 × 10-11 g m-1 Pa-1 s-1 and 48 to 97 cm3 mµ/m2 d kPa, respectively. Dark, red, yellow, and opaque films were realized with increasing PG. Fourier transform infrared (FTIR) spectra approved a wide peak of approximately 2500 cm-1. The rheological analysis indicated that, by adding PG, viscosity, elastic modulus (G') and loss modulus (G'') were increased significantly (p < 0.05) about 9.5, 9.32 and 18 times, respectively. Therefore, an easy modification of FG with PG will make it suitable for oil sachet packaging applications for the food industry.

Evolution of Virgin Olive Oil during Long-term Storage.

In this work, the evolution of virgin olive oil from 4 olive varieties when stored at 5°C, 10°C and 20°C for a period of up to 3 years was studied. Free acidity increased progressively for the 4 varieties, staying below the limit for extra virgin olive oil, even at the highest temperature. The peroxide value also increased, reaching its maximum after about 28 months of storage, when some samples stored at 20°C exceeded the limit for extra virgin olive oil. The maximum values for K270 and K232 were reached at the end of the storage period, also exceeding the limit for extra virgin olive oil in the case of some varieties stored at 20°C. Oxidative stability decreased by 38%-50% depending on the storage temperature and the variety. Most of the color indexes increased in value because of the degradation of the oil pigments.

Efecto de cocción en horno convencional y microondas sobre rancidez, pérdida por cocción y diferencia sensorial de hamburguesas / Effect of conventional oven versus microwave cooking on rancidity, cooking loss and sensory difference of hamburger patties

El uso de microondas está muy extendido a nivel doméstico gracias a su rapidez y facilidad de uso. El objetivo del presente trabajo es comparar el efecto de cocción de hamburguesas de distintos tipos de carne, en microondas y en horno convencional, sobre la pérdida de peso y estabilidad oxidativa. Además, determinar si existen diferencias desde el punto de vista sensorial aplicando una prueba triangular, comparando 2 productos presentados en tríos, uno que corresponde a hamburguesa cocida en microondas y otro a hamburguesa cocida en horno convencional. Se adquirieron hamburguesas de pollo, pavo, cerdo y vacuno en el comercio, se cocinaron en horno convencional y en microondas. Se calculó pérdida por cocción, se evaluó la rancidez y diferencias sensoriales entre hamburguesas del mismo tipo de carne, cocidas en distinto tipo de horno. La pérdida por cocción fue menor en hamburguesas cocidas en microondas. La acidez e índice de peróxido aumentaron en las muestras cocidas en ambos tipos de hornos respecto a hamburguesas crudas. La acidez fue mayor en hamburguesas cocidas en horno convencional, y el índice de peróxido fue mayor en hamburguesas cocidas en microondas, llegando a 10,6 meq O2/kg. En el análisis sensorial se encontraron diferencias significativas (p<0,05) entre las hamburguesas cocidas en horno convencional y en microondas. Resulta mejor opción cocinar hamburguesas en horno convencional, ya que el índice de peróxidos es menor que al cocinar en microondas; dentro del tipo de hamburguesas, son más estables las de vacuno y cerdo frente a la oxidación.

The use of microwaves is very widespread at the domestic level thanks to its speed and ease of use. The aim of this study was to compare cooking loss, rancidity and sensory differences for hamburger patties cooked in conventional versus microwave ovens. We also determined sensorial differences with the triangular test, comparing two products presented in threesomes, one that corresponded to a patty cooked in the microwave and the other in a conventional oven. Chicken, turkey, pork and beef patties were purchased commercially, cooked in a conventional oven and in microwaves. Cooking loss was calculated, rancidity and sensory differences were evaluated between patties of the same type of meat and cooked in the different oven types. Cooking loss was lower in patties cooked in microwaves compared to those cooked in conventional ovens. For both oven types, acidity and peroxide index increased with respect to raw ones. Acidity was higher in hamburgers cooked in conventional ovens and the peroxide index was higher in burgers cooked in microwaves, reaching 10.6 meq O2/kg. In sensory analysis, significant differences were found (p<0.05) between patties cooked in a conventional oven and in microwaves. It is a better option to cook patties in a conventional oven, because the peroxide index is smaller than in microwaves; and within types of patties, beef and pork are more stable against oxidation.

Effect of Drying Operating Conditions on Canola Oil Tocopherol Content.

The aim of this work was to evaluate two operating parameters of seed drying (temperature and initial moisture content) on the tocopherol content of canola oil. The raw material was characterized by moisture, oil, protein, crude fiber and ash content. Seeds at 13.6% and 22.7% moisture content (dry basis, db) were dried at temperatures in the range of 35-100 °C to a safe storage moisture of 7% db. Oil was extracted from each treated sample. The oil extracted from the samples dried at the extreme temperatures was analyzed by means of the acidity value, peroxide index and fatty acid composition, finding no significant differences among treatments or among untreated and treated samples. Tocopherol contents in the oils obtained for all the assayed temperatures were determined. Differences were found for the samples with 22.7% (db) initial moisture content. Except at 35 °C, temperature affected negatively the oil tocopherol content. However, when 13.6% (db) moisture seeds were processed, no significant differences were observed in the amount of this minor oil component among assays.

Avaliação da qualidade de óleos e gorduras de fritura em bares, restaurantes e lanchonetes / Assessment of used frying oils and fats in bars, restaurants and snack bars

Com o objetivo de avaliar a qualidade de óleos e/ou gorduras utilizados para fritura por imersão em bares, restaurantes e lanchonetes, foram coletadas 180 amostras de óleo e/ou gordura, sendo 90 antes e 90 após fritura. Aplicou-se um questionário para avaliar as técnicas de fritura e a infra estrutura dos estabelecimentos. Foram realizados os métodos analíticos para avaliar a alteração dos óleos e gorduras a saber, compostos polares totais (%), acidez (mgKOH/g) e índice de peróxido (mEq/kg). Das 90 amostras coletadas antes da fritura, 18,18 % demonstraram valores de compostos polares superiores ao limite estabelecido (5%), predominantemente nas amostras coletadas de lanchonetes. Quanto aos compostos polares totais, acidez e índice de peróxidos para óleos e gordura de fritura, 7,78%, 12,22 % e 2,22 % das amostras, respectivamente, apresentaram valores acima dos limites estabelecidos para efetuar o descarte. A avaliação das técnicas de fritura demonstrou dados insatisfatórios, tais como falta de controle da temperatura, tipo de óleo e equipamentos empregados. Os resultados obtidos indicam a necessidade de ações educativas no setor, assim como efetiva fiscalização por parte dos órgãos competentes.

Aiming at assessing the quality of oils and fats employed for frying food in bars, restaurants and snack bars, 180 samples were analyzed, from which 90 were collected before use and 90 after the frying process. A questionnaire was used in order to collect information on food frying procedures and on the respective food-serving places infrastructure. The analysis on alterations in oil and fat samples was performed by using the following analytical methods: total polar compounds (%), free fatty acid (mg KOH/g) and peroxide index (meq/kg). Among the 90 samples collectedbefore the frying procedure, 18.18% showed higher values of polar compounds over the established limit (5%), predominantly in samples collected from snack bars. In 7.78%, 12.22% and 2.22% of the analyzed frying oil and fat samples, the total polar compounds, free fatty acids and peroxide indices, respectively, were in a higher rate than those limit values established for discarding them. The inadequacy on the employed frying procedure was observed as this process was performed without control over the frying temperature, type of oil, and employed equipment.These findings indicate that the food-service locations require close surveillance supervisions.