Modelling the shelf-life of minimally-processed fresh-cut apples packaged in a modified atmosphere using food quality parameters

Comparative physiological and transcriptomic analysis reveals an improved biological control efficacy of Sporidiobolus pararoseus Y16 enhanced with ascorbic acid against the oxidative stress tolerance caused by Penicillium expansum in pears

Sporidiobolus pararoseus Y16, a species of significant ecological importance, has distinctive physiological and biological regulatory systems that aid in its survival and environmental adaptation. The goal of this investigation was to understand the complex interactions between physiological and molecular mechanisms in pear fruits as induced by S. pararoseus Y16. The study investigated the use of S. pararoseus Y16 and ascorbic acid (VC) in combination in controlling blue mold decay in pears via physiological and transcriptomic approach. The study results showed that treatment of S. pararoseus Y16 with 150 μg/mL VC reduced pears blue mold disease incidence from 43% to 11%. Furthermore, the combination of S. pararoseus Y16 and VC significantly inhibited mycelia growth and spore germination of Penicillium expansum in the pear's wounds. The pre-treatment did not impair post-harvest qualities of pear fruit but increased antioxidant enzyme activity specifically polyphenol oxidase (PPO), peroxidase (POD), catalase (CAT) activities as well as phenylalanine ammonia-lyase (PAL) enzyme activity. The transcriptome analysis further uncovered 395 differentially expressed genes (DEGs) and pathways involved in defense mechanisms and disease resistance. Notable pathways of the DEGs include plant-pathogen interaction, tyrosine metabolism, and hormone signal transduction pathways. The integrative approach with both physiological and transcriptomic tools to investigate postharvest pathology in pear fruits with clarification on how S. pararoseus Y16 enhanced with VC, improved gene expression for disease defense, and create alternative controls strategies for managing postharvest diseases.

Insights into application progress of seafood processing technologies and their implications on flavor: a review

Seafood tends to be highly vulnerable to spoilage and deterioration due to biochemical reactions and microbial contaminations, which requires appropriate processing technologies to improve or maintain its quality. Flavor, as an indispensable aspect reflecting the quality profile of seafood and influencing the final choice of consumers, is closely related to the processing technologies adopted. This review gives updated information on traditional and emerging processing technologies used in seafood processing and their implications on flavor. Traditional processing technologies, especially thermal treatment, effectively deactivate microorganisms to enhance seafood safety and prolong its shelf life. Nonetheless, these methods come with limitations, including reduced processing efficiency, increased energy consumption, and alterations in flavor, color, and texture due to overheating. Emerging processing technologies like microwave heating, infrared heating, high pressure processing, cold plasma, pulsed electric field, and ultrasound show alternative effects to traditional technologies. In addition to deactivating microorganisms and extending shelf life, these technologies can also safeguard the sensory quality of seafood. This review discusses emerging processing technologies in seafood and covers their principles, applications, developments, advantages, and limitations. In addition, this review examines the potential synergies that can arise from combining certain processing technologies in seafood processing.

Toxicity, formation, contamination, determination and mitigation of acrylamide in thermally processed plant-based foods and herbal medicines: A review

Thermal processing is one of the important techniques for most of the plant-based food and herb medicines before consumption and application in order to meet the specific requirement. The plant and herbs are rich in amino acids and reducing sugars, and thermal processing may lead to Maillard reaction, resulting as a high risk of acrylamide pollution. Acrylamide, an organic pollutant that can be absorbed by the body through the respiratory tract, digestive tract, skin and mucous membranes, has potential carcinogenicity, neurological, genetic, reproductive and developmental toxicity. Therefore, it is significant to conduct pollution determination and risk assessment for quality assurance and security of medication. This review demonstrates state-of-the-art research of acrylamide focusing on the toxicity, formation, contamination, determination, and mitigation in taking food and herb medicine, to provide reference for scientific processing and ensure the security of consumers.

Ferulic Acid Treatment Maintains the Quality of Fresh-Cut Taro (Colocasia esculenta) During Cold Storage

Taro (Colocasia esculenta) is a major root crop or vegetable in the world, and the corm is a good source of many nutrients including starch, vitamins, and minerals. Taro corms are processed into various forms before consumption, which makes them perishable, reduces the shelf life, and increases postharvest losses. The surface browning of fresh-cut taros is one of the major factors that limits storage life and affects consumer acceptance. In this study, the effects of ferulic acid (FA) as an effective agent in the prevention of quality deterioration were investigated. Fresh-cut taros were immersed in distilled water and different concentrations of FA (1, 2, 5, 10, and 20 mM) solutions for 30 min, air-dried at 25°C for 30 min, and then stored at 5°C for 12 days to investigate the effects of FA on browning. Among the FA concentrations tested, 10 mM resulted in significantly higher L * values, lower a * and b *, and browning index values. FA treatment (10 mM) also induced de novo biosynthesis of two volatile compounds, including non-anal and octanoic acid ethyl ester in fresh-cut taros following extended cold storage. The results suggest that FA treatment maintains the quality of fresh-cut taros under cold conditions. FA treatment enhanced PAL activity and gene expression but reduced total phenolic content and the expression of six C4H, 4CL, and CHS genes, suggesting that FA treatment reduced phenolic biosynthesis. FA treatment reduced PPO activity and gene expression and decreased soluble quinone content, suggesting that FA treatment suppressed the phenolic oxidation. FA treatment enhanced the activity and gene expression of CAT and POD, reduced those of LOX, and decreased MDA and H2O2 levels, suggesting that FA treatment activated the antioxidant defense system and thereby reduced oxidative damage. These findings demonstrated that FA treatment could serve as an effective approach to retard the browning of fresh-cut taros and provided a basis for the feasible application of FA in the preservation of fresh-cut foods.

Assessment of the Microbiological Quality of Ready-to-Eat Salads-Are There Any Reasons for Concern about Public Health?

Ready-to-eat food products can be readily consumed without further preparation and are convenient for busy on-the-go consumers. The objective of the study was to assess the microbiological quality of ready-to-eat salads. Thirty RTE salads were tested for the presence of bacteria, yeasts, and molds using the TEMPO and agar plate method. The study demonstrated that most of the tested products were characterized by varying microbiological quality. The total number of mesophilic microbiotas was about 6 log CFU g^-1. The high number of microorganisms was due to yeast and molds or Enterobacteriaceae. Half of the salads were contaminated with E. coli and three salads were contaminated with S. aureus. LAB were also found, which can be explained mainly by a dairy ingredient. In some salads, Salmonella spp. and L. monocytogenes were detected (26.7% and 33.3% of the samples, respectively). Based on the conducted tests, it was found that the microbiological quality was not satisfactory. The results presented in this study indicate that there is a significant problem of the presence of pathogens. Manufacturers should strive to reduce the possibility of microbial contamination through the use of widely understood hygiene of the production process, using hurdle technology, including the modified atmosphere and refrigerated storage.

Growth behavior of low populations of Listeria monocytogenes on fresh-cut mango, melon and papaya under different storage temperatures

The growth behavior of Listeria monocytogenes low population (1-4 cells/sample) on fresh-cut mango, melon, papaya and fruit mix stored at 4, 8, 12 and 16 °C was evaluated over 10 days. Mango showed the lowest counts for L. monocytogenes during 10 days regardless of storage temperature (<1.7 log cfu.g^-1). Melon supported high bacterial growth over 10 days, reaching 5 log cfu.g^-1 at 16 °C. Both the fruit and storage temperature influenced the Listeria low population growth potential (δ). Cumulative frequency distribution of L. monocytogenes showed that after 10 days, 100% of fresh-cut fruits and fruit mix stored at 4 °C remained ≤2 log cfu.g^-1, while at 12 and 16 °C 100% of melon, papaya and fruit mix samples exceeded this limit. At 8 °C, 100% of mango and fruit mix samples remained below this limit after 10 days, whereas 100% of melon and papaya reached it after 7 days. Results indicate 4 °C as the ideal to store safely fresh-cut mango, melon, papaya and fruit mix for 10 days. Besides, 8 °C can also be an option, but not for melon and papaya. Findings highlight the ability of L. monocytogenes to survive and grow in fresh-cut fruits even at a very low initial population levels.

Decontamination of Food Packages from SARS-CoV-2 RNA with a Cold Plasma-Assisted System

The accidental contamination of food and food packaging surfaces with SARS-CoV-2 is of increasing concern among scientists and consumers, particularly in relation to fresh foods that are consumed without further cooking. The use of chemical sanitizers is often not suitable for these kinds of commodities; therefore, a non-thermal sanitation technology could help to increase safety in relation to the food supply chain. Cold plasma has proven to be a promising strategy for virus inactivation. This research is aimed at evaluating the ability of a cold plasma sanitation system to inactivate SARS-CoV-2 RNA on packaged foods. Two different plastic materials were investigated and subjected to 5- and 10-min exposure to plasma after experimental inoculum of the RNA. In addition to viral degradation, possible changes in the performance of the materials were evaluated. Shelf-life of the foods, after exposure of the packages to plasma, was also investigated. Results showed that 10 min of exposure was sufficient to almost completely eliminate the viral RNA from package surfaces. The treatment did not produce any significant variation in packaging material performance or the shelf-life of the tested packaged products, indicating the potentiality of this treatment for the decontamination of packaged products.

The Use of Modeling Tools to Better Evaluate the Packaging Benefice on Our Environment

Packaging play a key role on food quality preservation and shelf-life increase. Even if the link between shelf life and food loss has not yet clearly been formalized, it is generally observed that a well-designed packaging contributes to reduce food loss and waste and thus the corresponding useless negative impact that producing and distributing uneaten or inedible food has on our environment and economy. In order to anticipate the usage benefit of a given packaging, decision making tools are needed to be developed. While some authors' separately showed the importance of shelf life model, food loss and waste prediction model and Life Cycle Analysis, so far no connection was really made between them. In this context, this paper aims to analyze the different mathematical modeling approaches proposed in the available scientific literature, from the prediction of food shelf life gain thanks to well-designed packaging to the environmental benefice due to the decrease of food loss and waste. The article presents a review of 29 models developed on this thematic during the last two decades. The analyzed models were split in three categories: (1) the food shelf life models, (2) the models linking shelf life to food loss and waste, and (3) the Life Cycle Analysis including direct (production, processing and end of life) and indirect (food loss and waste) packaging environmental impacts. In one hand, the review showed that if many predicting approaches were conducted to assess food shelf life, only few of them were enough mechanistic (by coupling mass transfer to food deterioration) to be used in other conditions than the ones initially studied. Moreover, the consumers' practices and believes being strongly influent on the quantity of food waste at household, it should be more systematically integrated in the food loss and waste estimation for a fairer evaluation. On the other hand, this review highlighted that even if indirect environmental benefit of packaging, e.g., through food loss and waste decrease, is more and more integrated in life cycle analyses of the food packaging system, most of studies were only based on rough estimation and not on real quantification of the food loss and waste reduction obtained thanks to the well-designed packaging. Therefore, further research is needed to facilitate the representation/quantification of the links between shelf life increase for packed food, resulting food loss and waste reduction and environmental benefit to support the packaging sectors to choose and validate the best packaging solution to decrease the environmental impact of food/packaging system.

Storage quality of fresh-cut apples treated with yerba mate (Ilex paraguariensis)

Dipping fresh-cut fruits in antioxidant solutions is a useful method to avoid enzymatic browning. Yerba mate extracts have a high content of antioxidant compounds and could be a natural alternative to control browning and improve the bioactive properties of fresh-cut apples. Therefore, this study aimed to evaluate the performance of an antioxidant solution of yerba mate (1.2%), citric acid (0.9%) and ascorbic acid (1.0%) with water as control, on fresh-cut 'Granny Smith' apples during storage at 2 °C (18 days) and 10 °C (15 days) under MAP. Physicochemical characteristics, bioactive properties, sensory attributes, microbial quality as well as the gas composition within the packages were analyzed throughout storage. Samples from both treatments showed a slower quality loss at 2 °C than at 10 °C. The antioxidant solution increased the lag-phase of molds, mesophilic and psychrotrophic microorganisms stored at 2 °C. The phenolic compounds of yerba mate together with ascorbic acid, not only increased the antioxidant capacity of the fresh-cut apples but also reduced the enzymatic browning at both temperatures, increasing the storage time in 2-5 days with an acceptable appearance, when compared to control samples. The antioxidant solution containing yerba mate provided the fresh-cut apples with a higher content of healthy compounds throughout storage at both temperatures.

Aplicação do ultrassom no processamento de frutas e hortaliças

Resumo Este trabalho objetivou apresentar aspectos relacionados à utilização do ultrassom no processamento de frutas e hortaliças, como o funcionamento do método, os efeitos no alimento, as aplicações, os aspectos sensoriais e a percepção dos consumidores. As mudanças dos hábitos alimentares e a busca do bem-estar refletem no aumento da procura por alimentos naturais, como as frutas e as hortaliças. Estes alimentos podem sofrer alterações microbiológicas ao longo da cadeia produtiva, sendo necessária a aplicação de boas práticas agrícolas e de manipulação, e processos tecnológicos de conservação para a garantia da qualidade do produto. O ultrassom é uma tecnologia emergente aplicada no processamento de frutas e hortaliças que está relacionada a melhorias na qualidade e preservação. O princípio básico do ultrassom é a cavitação acústica, que envolve o crescimento e colapso de bolhas durante períodos de rarefação e compressão, causando alterações químicas, físicas e mecânicas no alimento. Essas alterações estão relacionadas à inativação de micro-organismos e de enzimas, à remoção de resíduos e às melhorias na qualidade físico-química, e à acessibilidade de compostos bioativos. Além disso, a aplicação deste método pode ter boa aceitabilidade pelos consumidores, que procuram alimentos mais naturais e submetidos a processos que não causem impacto ambiental.

Evaluation and modeling of changes in color, firmness, and physicochemical shelf life of cut pineapple (Ananas comosus) slices in equilibrium-modified atmosphere packaging

In this study cut, pineapple slices of 1 cm thick were packaged and stored at different temperatures and equilibrium modified atmosphere packages (EMAPs) to determine changes of color and firmness over time to represent physicochemical shelf life. From the experimental data, a variance analysis was performed to determine the effect of temperature and O₂ level on the evolution of color (CIELAB coordinates) and firmness. It was observed that the evolution in L^* , a^* , and b^* coordinates is independent on O₂ concentration in the EMAP system. After that, suitable models were adjusted to represent the change of the quality properties as a function of temperature by using first-order models to represent color and a power model for firmness. Likewise, a modified normal distribution function was adjusted to represent the coefficient of firmness loss depending on the O₂ level besides the temperature effect. The firmness model was used to obtain a suitable equation to predict shelf life of the pineapple slices for different EMAP systems. Finally, a validation experiment was performed at 8 °C obtaining a high capacity of prediction (R² _adj > 0.90) compared with the experimental data. The adjusted model can be used to configure a satisfactory EMAP system for the best preservation of minimally processed pineapple from the predicted evolution of color, firmness, and shelf life depending on temperature and O₂ concentration. PRACTICAL APPLICATION: In this work, we built a mathematical model to simulate the shelf life of pineapple cut into slices based on changes in color and firmness and as a function of temperature and oxygen level. These properties are truly relevant because they are very clear evidence of the fruit deterioration, and for that reason, we chose them for the model. The model we developed can be applied in retail and supermarket systems to determine precisely how long the product on the shelf can last before being disposed of, reducing material losses.

Fresh-cut potato quality and sensory: Effect of cultivar, age, processing, and cooking during storage

This work examined the influence of cultivar, tubers' age, antibrowning agent, package atmosphere, and storage time on fresh-cut potatoes' (FCPs) physical, chemical, and sensory properties. Potato slices of cv. Birgit and Lady Claire tubers sampled during the first, fifth, and ninth months of storage were dipped in solutions of (1) sodium chloride (1%) and (2) sodium ascorbate (2%), and stored for 8 days in (1) vacuum and (2) active modified atmosphere (MAP) (10.0% CO₂ , 3.0% O₂ , and 87.0% N₂ ) at 10 °C. During storage, O₂ and CO₂ content (%) within packages was measured and samples were analyzed for weight loss, total solids (TS) and soluble solids (SS), pH, color, texture, and sensory properties of raw, boiled, fried, and baked FCP. Results showed that 9 months' aging had a significant impact on almost all investigated FCP properties, but differences among first, fifth, and ninth months were numerically feeble for some parameters in raw samples: TS changed from 22.14% to 20.98%, SS 5.53% to 6.93%, pH 6.02 to 5.98, L^* 70.10 to 68.87, C^* 35.75 to 36.70, H° 89.29 to 88.15, and firmness 7.25 to 8.13N. Furthermore, 9 months of aging had no significant influence on the characteristic odor of raw, boiled, fried, and baked FCP and characteristic taste of fried and baked FCP, whereas boiled FCP characteristic taste remained unchanged for 5 months of aging. Fried FCP was better sensory evaluated than baked ones, cv. Birgit was more suitable for the FCP production compared to cv. Lady Claire as well as vacuum packaging and sodium ascorbate better preserved samples quality and sensory than sodium chloride and MAP. PRACTICAL APPLICATION: This study could be helpful to fresh-cut potato (FCP) producers because results indicate that for FCP processing, along with the selection of cultivar, antibrowning agent, and packaging type, tubers' age also requires attention. A further contribution of this research is related to the adequate way of FCP cooking, where frying shows the best results according to the quality and sensory assessment.

Influence of Preharvest Gibberellic Acid Treatments on Postharvest Quality of Minimally Processed Leaf Lettuce and Rocket

Plant growth regulators are used in high-value vegetable crops during cultivation and after harvest to increase yield, enhance crop management, and improve or retain the produce quality. The aim of this work was to evaluate the quality characteristics during cold storage of minimally processed leaf lettuce and rocket, obtained from plants grown in a hydroponic floating system with mineral nutrient solutions (MNS) containing different levels of gibberellic acid (GA3). Plants were grown in greenhouse conditions on nutrient solutions containing 0, 10−8, and 10−6 M GA3. At harvest, lettuce and rocket were immediately processed as fresh-cut vegetables and stored for 21 d at 4 °C. After processing, weight loss, total soluble solids, titratable acidity, ascorbic acid and nitrate content, leaf color characteristics, and overall quality were evaluated. Adding 10−6 M GA3 to the MNS of a floating system significantly increased the yield of leaf lettuce and rocket plants and of minimally-processed leaves. In addition, preharvest GA3 treatments had positive effects on delaying senescence and enhancing shelf-life of minimally processed lettuce and rocket. The slowed senescence of GA3-treated samples maintained an overall quality over the threshold of marketability in both lettuce and rocket for up to 21 d of cold storage.

Reduction of Escherichia coli O157:H7 and naturally present microbes on fresh-cut lettuce using lactic acid and aqueous ozone

Lactic acid (LA) is an effective sanitizer for disinfection of fresh produce. Tap water is generally used to wash disinfected fresh produce because sanitizer residues negatively affect the quality and organoleptic properties of the produce. However, tap water is ineffective for secondary disinfection compared with sanitizers. Thus, we propose a disinfection method using LA plus aqueous ozone (AO), an oxidizing sanitizer that does not lead to secondary residue. We compared the proposed method of 1% LA (90 s) plus 1 mg L-1 AO (30 s) or 2 mg L-1 AO (30 s) with the traditional method of 100 ppm chlorine (120 s) or 1% LA (120 s) plus tap water (30 s) and 2 mg L-1 AO (150 s). Microbial analysis showed that LA plus AO led to the greatest reductions in microbes (Escherichia coli O157:H7, aerobic mesophilic counts, aerobic psychrophilic counts, moulds, and yeasts) during storage (0-5 days at 5 °C). Quality analysis (colour, sensory qualities, electrolyte leakage, polyphenolic content, and weight loss) showed that LA + AO did not cause additional quality loss compared with tap water treatment. These results indicate that the hurdle technology proposed (LA plus AO) has a good potential for use in fresh produce disinfection.

Novel Food Processing and Extraction Technologies of High-Added Value Compounds from Plant Materials

Some functional foods contain biologically active compounds (BAC) that can be derived from various biological sources (fruits, vegetables, medicinal plants, wastes, and by-products). Global food markets demand foods from plant materials that are “safe”, “fresh”, “natural”, and with “nutritional value” while processed in sustainable ways. Functional foods commonly incorporate some plant extract(s) rich with BACs produced by conventional extraction. This approach implies negative thermal influences on extraction yield and quality with a large expenditure of organic solvents and energy. On the other hand, sustainable extractions, such as microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), high-pressure assisted extraction (HPAE), high voltage electric discharges assisted extraction (HVED), pulsed electric fields assisted extraction (PEF), supercritical fluids extraction (SFE), and others are aligned with the “green” concepts and able to provide raw materials on industrial scale with optimal expenditure of energy and chemicals. This review provides an overview of relevant innovative food processing and extraction technologies applied to various plant matrices as raw materials for functional foods production.

Enzymatic, physicochemical, nutritional and phytochemical profile changes of apple (Golden Delicious L.) juice under supercritical carbon dioxide and long-term cold storage

The impact of supercritical carbon dioxide (SCCD) (10-60 MPa/45 °C/30 min) and subsequent 10 weeks storage at 4 °C on polyphenol oxidase (PPO), peroxidase (POD) activities, phenolic profile, vitamin C, sugars, physicochemical properties of cloudy apple juices was investigated. No significant changes in sugars and total polyphenols were observed, whereas significant degradation (≈28%) of vitamin C and individual polyphenols (≈18%) was noted after SCCD treatment. After 4 weeks storage only 34% of vitamin C was retained and no vitamin C was detected after this time. Ten weeks of storage caused hydrolysis of sucrose in 15%, whereas degradation of individual polyphenols ranged from 43 to 50% depending on the pressure applied. The highest pressure was applied the highest retention of polyphenols was observed. The lightness of juice significantly increased by 15% after SCCD and decreased during storage. Moreover, the synergistic effect of both enzymes with chlorogenic acid and catechol was found.

Trends in Chemometrics: Food Authentication, Microbiology, and Effects of Processing

In the last decade, the use of multivariate statistical techniques developed for analytical chemistry has been adopted widely in food science and technology. Usually, chemometrics is applied when there is a large and complex dataset, in terms of sample numbers, types, and responses. The results are used for authentication of geographical origin, farming systems, or even to trace adulteration of high value-added commodities. In this article, we provide an extensive practical and pragmatic overview on the use of the main chemometrics tools in food science studies, focusing on the effects of process variables on chemical composition and on the authentication of foods based on chemical markers. Pattern recognition methods, such as principal component analysis and cluster analysis, have been used to associate the level of bioactive components with in vitro functional properties, although supervised multivariate statistical methods have been used for authentication purposes. Overall, chemometrics is a useful aid when extensive, multiple, and complex real-life problems need to be addressed in a multifactorial and holistic context. Undoubtedly, chemometrics should be used by governmental bodies and industries that need to monitor the quality of foods, raw materials, and processes when high-dimensional data are available. We have focused on practical examples and listed the pros and cons of the most used chemometric tools to help the user choose the most appropriate statistical approach for analysis of complex and multivariate data.

Effect of Grinding at Modified Atmosphere or Vacuum on Browning, Antioxidant Capacities, and Oxidative Enzyme Activities of Apple

This study evaluated the effects of grinding at atmospheric pressure (control), under vacuum (∼2.67 kPa), or with modified atmosphere (N₂ and CO₂ ) on the browning, antioxidant activity, phenolics, and oxidative enzyme activity of apples as a function of time. The control group was affected most, showing distinct browning and losing most of the antioxidant activity and concentrations of the main phenolic compounds. The modified atmosphere groups retained color, antioxidant activity, and phenolic compounds better than the control group. Least changes were obtained with vacuum grinding, particularly in terms of preventing enzymatic browning and oxidation of antioxidants apples. At 12 h after grinding, vacuum-ground apples retained total phenolic contents 5.32, 1.54, and 1.49 times higher than control, nitrogen gas, and carbon dioxide gas-ground samples, respectively. The oxidative enzyme activity, including that of polyphenol oxidase and peroxidase, decreased in the control and modified atmosphere group, but they were maintained in the samples ground under the vacuum.

PRACTICAL APPLICATION

In this study, we found that grinding with modified atmosphere or vacuum conditions could effectively prevent browning as well as loss of phenolic compounds and antioxidant activity of ground apples. These results can help scientists and engineers build better grinding systems for retaining nutrient and quality factors of ground apples. In addition, these results may be useful to other fruit and vegetable industries that wish to retain fresh-like quality and nutritional value during grinding and storage.