A kinetic study of furan formation during storage of shelf-stable fruit juices

Effects of Hydrothermal Processing on Volatile and Fatty Acids Profile of Cowpeas (Vigna unguiculata), Chickpeas (Cicer arietinum) and Kidney Beans (Phaseolus vulgaris)

Legumes are an economical source of protein, starch, dietary fibre, fatty acids, vitamins and minerals. However, they are not as fully utilised, due to volatile compounds contributing to their undesirable odour. The purpose of this work was to understand the processing time's effect on the legumes' volatile profile. Hence, this study investigated the effects of hydrothermal processing times on the volatile and fatty acids profiles of cowpeas, chickpeas and kidney beans. All legumes were pre-soaked (16 h) and then hydrothermally processed at 95 °C for 15 to 120 min, using an open system to approximate standard household cooking practices and a closed system to represent industrial processing. Alcohol, aldehyde, acid and ester volatile compounds showed decreasing trends during processing, which can be associated with enzyme inactivation and process-induced degradation. This work showed that processing at 95 °C for 30 min significantly reduced the number of compounds commonly associated with undesirable odour, but showed no significant change in the fatty acid profile. Other volatiles, such as furanic compounds, pyrans and sulphur compounds, showed an increasing trend during processing, which can be related to the Maillard reactions. This observation contributes to the growing knowledge of legume processing and its impact on volatile flavour. It can advise consumers and the industry on selecting processing intensity to maximise legume utilisation.

Investigation of thermal contaminants in coffee beans induced by roasting: A kinetic modeling approach

The roasting-induced formation of thermal contaminants in coffee beans, including 5-hydroxymethylfurfural (5-HMF), acrylamide (AA), furan (F), 2-methyl furan (2-MF), and 3-methyl furan (3-MF), was investigated using a kinetic modeling approach. Results showed that AA and 5-HMF formation and elimination occur simultaneously in coffee beans during roasting and that the related reactions follow first-order reaction kinetics. The concentrations of F, 2-MF, and 3-MF increased throughout the roasting experiment, and variations in the concentrations of these compounds during roasting could be best described by empirical, logistic model. The increase in weight loss and decrease in moisture content of the beans during roasting also displayed first-order reaction kinetics. High coefficients of determination (R² > 0.981) were observed for all fitted models, and the reaction rate constants of all models followed the Arrhenius law.

Variable Retort Temperature Profiles (VRTPs) and Retortable Pouches as Tools to Minimize Furan Formation in Thermally Processed Food

Furan and its derivates are present in a wide range of thermally processed foods and are of significant concern in jarred baby and toddler foods. Furan formation is attributed to chemical reactions between a variety of precursors and a high processing temperature. Also, some kinetic models to represent its formation in different food materials have been studied and could predict the furan formation under simulated operating conditions. Therefore, this review aims to analyze and visualize how thermally processed foods might be improved based on optimal control of processing temperature and package design (e.g., retort pouches) to diminish furan formation and maximize quality retention. Many strategies have been studied and applied to reduce furan levels. However, an interesting approach that has not been explored is the thermal process design based on optimum variable retort temperature profiles (VRTPs) and the use of retortable pouches considering the microstructural changes of food along the process. The target of process optimization would be developed by minimizing the microstructural damage of the food product. It could be possible to reduce the furan level and simultaneously preserve the nutritional value through process optimization.

Effects of processing parameters on furan formation in canned strawberry jam

The formation mechanism of furan has been studied extensively in model systems, however, furan formation in real foods are complex and far from being fully understood. In this study, the effects of acid-regulating agent (citric acid), sugar addition (glucose, fructose and sucrose) and thickening agents (xanthan gum, κ-carrageenan and pectin) on furan levels in strawberry jams were studied; meanwhile the formation pathway of furan in canned strawberry jam was proposed by carbon module labeling (CAMOLA) technique. Our results suggested low pH promoted furan formation in strawberry jam. Besides, fructose produces more furans than sucrose and glucose, and the addition of xanthan gum reduced furan levels significantly. The kinetic data showed that ascorbic and dehydroascorbic acid degradation followed first-order kinetics while rate of furan formation followed zero-order kinetics. This study presented the possibility of mitigating furan formation in canned strawberry jams by optimization of processing parameters and addition of xanthan gum.

Chemical Kinetic Modeling of Nutricereal based Fermented Baby Food for Shelf Life Prediction

Background:

A nutricereal based fermented baby food was investigated to predict its shelf life using chemical kinetic modeling. An optimized baby food formulation, packaged in metalized polyester packets was stored at accelerated conditions for 180 days and analyzed for Hydroxy Methyl Furfural (HMF), Thiobarbituric Value (TBA), Free Fatty Acid Content (FFA) and sensory characteristics.

Objective:

The objective of the study was to determine the shelf life of the optimized nutricereal based fermented baby food using chemical kinetic modeling.

Methods:

Chemical kinetics analysis by investigating the Hydroxymethyl Furfural content, thiobarbituric value (TBA), free fatty acid content (FFA) and sensory characteristics of the optimized baby food.

Results:

Shelf life model based on chemical and sensory acceptability was derived using Arrhenius equation modeling. Thus, the baby food had a predictive shelf life of 54 weeks when stored at 10°C in metalized polyester based on the chemical (HMF, TBA and FFA) and sensory (overall acceptability) characteristics. A most suitable model based on FFA was developed considering lowest root mean square (RMS) percentages and least deviations in actual and predicted values.

Conclusion:

Chemcial kinetics could be applied to determine the shelf life of the fermented baby foods. HMF, TBA and FFA play key role in the shelf life of the stored fermented product. A model based on FFA is most suitable to determine the shelf life of the powdered nutricereal based fermented baby food packged in metalized polyster, stored at 10°C.

LC method for the direct and simultaneous determination of four major furan derivatives in coffee grounds and brews

The simultaneous quantification of two potential genotoxic hydroxymethyl furan derivatives in coffee (furfuryl alcohol and 5‐hydroxymethylfurfural) alongside their carboxylic acid derivatives (2‐furoic acid and 5‐hydroxymethyl furoic acid, respectively) was carried out. Their extraction from ground roasted coffee using sonication, simple shaking or heat‐assisted shaking lead to similar results. A minimum of 97.3% of the four furan derivatives were extracted during the first extraction cycle using water, whereas methanol showed considerably lower extraction efficiency. A simple high‐performance liquid chromatography method coupled with diode array detection was developed for the simultaneous determination and was applied to roasted coffee extracts or brews. No sample pre‐treatment except for centrifugation was needed. The diode array detector was used to assess the purity of the peaks of interest in analyzed samples against authentic standards. The linearity according to Mandel, accuracy (recovery ≥ 89.9%) and precision (inter‐ and intraday relative standard deviation ≤ 4.5%) were checked. The values for the limit of detection and quantification ranged within 0.11–0.76 and 0.35–2.55 μg/mL, respectively. Filtered and espresso brews were analyzed for the four furan derivatives where furfuryl alcohol showed double the concentration of 5‐hydroxymethylfurfural and about ten times the concentrations of 2‐furoic acid or 5‐hydroxymethyl furoic acid.

Process-induced cell wall permeability modulates the in vitro starch digestion kinetics of common bean cotyledon cells

Cell wall barrier role during in vitro simulated digestion of starch in common bean cotyledon cells can be modified through variation of thermal processing intensity.

Risks for public health related to the presence of furan and methylfurans in food

The European Commission asked EFSA for a scientific evaluation on the risk to human health of the presence of furan and methylfurans (2-methylfuran, 3-methylfuran and 2,5-dimethylfuran) in food. They are formed in foods during thermal processing and can co-occur. Furans are produced from several precursors such as ascorbic acid, amino acids, carbohydrates, unsaturated fatty acids and carotenoids, and are found in a variety of foods including coffee and canned and jarred foods. Regarding furan occurrence, 17,056 analytical results were used in the evaluation. No occurrence data were received on methylfurans. The highest exposures to furan were estimated for infants, mainly from ready-to-eat meals. Grains and grain-based products contribute most for toddlers, other children and adolescents. In adults, elderly and very elderly, coffee is the main contributor to dietary exposure. Furan is absorbed from the gastrointestinal tract and is found in highest amounts in the liver. It has a short half-life and is metabolised by cytochrome P450 2E1 (CYP2E1) to the reactive metabolite, cis-but-2-ene-1,4-dialdehyde (BDA). BDA can bind covalently to amino acids, proteins and DNA. Furan is hepatotoxic in rats and mice with cholangiofibrosis in rats and hepatocellular adenomas/carcinomas in mice being the most prominent effects. There is limited evidence of chromosomal damage in vivo and a lack of understanding of the underlying mechanism. Clear evidence for indirect mechanisms involved in carcinogenesis include oxidative stress, gene expression alterations, epigenetic changes, inflammation and increased cell proliferation. The CONTAM Panel used a margin of exposure (MOE) approach for the risk characterisation using as a reference point a benchmark dose lower confidence limit for a benchmark response of 10% of 0.064 mg/kg body weight (bw) per day for the incidence of cholangiofibrosis in the rat. The calculated MOEs indicate a health concern. This conclusion was supported by the calculated MOEs for the neoplastic effects.

Kinetic study of furan and furfural generation during baking of cake models

This study describes the kinetics of furan and furfural generation in a cake model, for the first time. These process-induced compounds impact safety and sensory aspects of baked products. Understanding their generation with regards to process dynamics will serve food quality design. However, the complexity of real products makes this task challenging. This work provides a novel approach to understand and model chemical reactivity by implementing an inert cake model (starch, water and cellulose), specifically designed for mimicking a sponge cake structure. The addition of reaction precursors (glucose and leucine) to follow Maillard and caramelization reactions, resulted in browning and generated considerable levels of furanic compounds (up to 17.61ng/g for furan and 38.99μg/g for furfural, dry basis). Multiresponse data modeling resulted in a kinetic model which adequately describes experimental concentrations and makes it possible to estimate the degradation of precursors and the behavior of two hypothetic intermediates.

Determination of Stability from Multicomponent Pesticide Mixes

A study was conducted to evaluate the stability of 528 pesticides, metabolites, and contaminants prepared in large multicomponent mixes to enhance laboratory efficiency by allowing maximum use of the useful shelf life of the mixtures. Accelerated aging at 50 °C simulated 6 month, 1 year, and 2 year storage periods at -20 °C. Initial mixture composition was based on the instrument of analysis. After preliminary stability data had been obtained, mixtures were reformulated and re-evaluated. In all, 344 compounds showed satisfactory stability across all treatment groups, 100 compounds showed statistically significant changes between the control and the 6 month simulated storage period (27 with losses >20%), and the remainder showed borderline stability or were tested in one protocol. Stability behavior for organophosphates agreed with the proposed reaction mechanism responsible for acetylcholinesterase inhibition. A small number of compounds increased in response over time, suggesting the occurrence of degradation of precursor pesticides into these respective compounds.

Relative importance and interactions of furan precursors in sterilised, vegetable-based food systems

Mitigation strategies aimed at an intervention in the reaction pathways for furan formation (e.g., by adjusting precursor concentrations) might offer an additional route for furan reduction in sterilised, vegetable-based foods, without adverse effects on other food safety or quality attributes. As a first step towards product reformulation, the aim of the present study was to determine the relative importance and interactions of possible furan precursors in these types of foods. Based on an I-optimal experimental design, potato purée (naturally low in furan precursors) was spiked with known amounts of sugars, ascorbic acid, olive oil and β-carotene, and subjected to a thermal sterilisation. Significant correlations were observed between furan concentrations after thermal treatment and starting concentrations of ascorbic acid and monosaccharides (i.e., fructose and glucose). Ascorbic acid had a clear furan-reducing effect as an antioxidant by protecting (polyunsaturated) fatty acids against oxidative degradation. Fructose and glucose were the main precursors, which can most probably be attributed to their high, but realistic, concentrations in the product. The contributions of fatty acids and β-carotene were strongly dependent on redox interactions with other food constituents. In the same potato purées, only low concentrations (0-2 ng g(-1) purée) of 2-methylfuran were detected, indicating that the direct importance of the spiked food constituents as a precursor for methylfuran formation was rather small. Based on the results of this study, reducing the amount of monosaccharides or adjusting the redox conditions of the matrix are suggested as two possible approaches for furan mitigation on the product side.