Films of polylactic acid with graphene oxide-zinc oxide hybrid and Mentha longifolia essential oil: Effects on quality of refrigerated chicken fillet.

This study was conducted to investigate the morphological, thermal, mechanical, FTIR, physicochemical (thickness, humidity, solubility in water and water vapor permeability) and antimicrobial properties of polylactic acid film (PLA) containing hybrid graphene oxide­zinc oxide (GO-ZnO: 1.5 % w/v) and Mentha longifolia essential oil (ML:1 % v/v) on chicken fillet kept in the refrigerator. The studied groups were microbially (total count of mesophilic aerobic bacteria, psychrotrophic bacteria, Enterobacteriaceae, Staphylococcus aureus, and lactic acid bacteria), chemically (pH, TVB-N) and sensory (color, odor, and taste) evaluated at 8-day interval (0, 2, 5 and 8). In the examination of the morphological characteristics, the PLA film had a smooth and uniform surface and the addition of ML essential oil created a discontinuous structure and the addition of GO-ZnO led to the production of a denser and more homogeneous film. The presence of GO-ZnO increased the thickness, decreased moisture content and solubility in water, and added ML essential oil increased moisture content and decreased solubility in water (p˂0.05). The results of the mechanical evaluation showed that the addition of ML essential oil and GO-ZnO reduced elongation at break and tensile strength (p˂0.05). The addition of ML essential oil increased the thermal resistance and the addition of GO-ZnO decreased the thermal resistance compared to the film containing ML essential oil. The antimicrobial effect of films containing ML essential oil was confirmed in this study (p˂0.05). The addition of GO-ZnO did not change the count of any of the microbial groups. TVB-N showed that groups containing ML essential oil had lower levels of volatile nitrogenous bases than the control group (p˂0.05). Sensory evaluation of the studied groups showed that chicken fillets packed with films containing ML essential oil had the highest score in terms of color, smell and taste. The results of the present study showed that PLA film containing GO-ZnO and ML essential oil can be used to increase the shelf life and maintain the sensory characteristics of chicken fillets, and it can be used as a suitable packaging to increase the shelf life of food products.

"Reference sample comparison method": A new voltammetric electronic tongue method and its application in assessing the shelf life of fresh milk.

Shelf life is a critical comprehensive indicator of food quality. Voltammetric electronic tongue (V-Et), is well-suited for assessing food shelf life, due to its capable of capturing food overall fingerprints. This study designed a "reference sample comparison method" for V-Et to assess the shelf life of fresh milk. Quality differences between milk samples of different shelf lives and reference samples were quantified by differential degree (Dd) values. A new "one-to-one" model of milk shelf life was established based on Dd values, and significantly improved predictive accuracy by 11.14 %-17.17 % and 14.86 %-44.47 % in overall quality shelf life assessment compared to "many-to-one" models based on SVM and DFA. Even in the more sophisticated evaluation of microbial safety and sensory quality shelf life, it attained relative errors of 13.57 % and 7.68 %, respectively. All these findings showed the significant potential of the "reference sample comparison method" in assessing food shelf life with V-Et.

Changes in volatile flavors during the fermentation of tomato (Solanum lycopersicum L.) juice and its storage stabilization.

Flavor is a crucial indicators of the quality of fermented tomato juice; however, there has been limited research in this area. Herein, headspace solid-phase microextraction gas chromatography-mass spectrometry was used to analyze the volatile metabolites at different stages during FTJ fermentation. 131 volatile organic compounds (VOCs) were identified, with alcohols, acids, and esters as the main compounds. The content of superoxide dismutase (SOD) and lycopene (LYC) had a positive correlation with methyl salicylate, ethyl acetate, and linalyl acetate. Subsequently, the storage stability of FTJ was evaluated at temperatures of 4 °C, 25 °C, and 37 °C over a period of 45 d, revealing that the quality of FTJ decreased with increasing storage temperature. The shelf life of FTJ under different storage conditions was determined using SOD activity and LYC content as quality indicators. The final shelf life was 47 d at 37 °C, 69 d at 25 °C, and 123 d at 4 °C.

Development of antifouling antibacterial polylactic acid (PLA) -based packaging and application for chicken meat preservation.

Microbial contamination is the leading cause of food spoilage and food-borne disease. Here, we developed a multifunctional surface based on polylactic acid (PLA) bioplastic with antifouling and antibacterial properties via a facile dual-coating approach. The surface was designed with hierarchical micro/nano-scale roughness and low surface energy. Bactericidal agent polyhexamethylene guanidine hydrochloride (PHMG) was incorporated to endow the film with bactericidal activity. The film had good superhydrophobic, antifouling and antibacterial performance, with a water contact angle of 154.3°, antibacterial efficiency against E. coli and S. aureus of 99.9 % and 99.6 %, respectively, and biofilm inhibition against E. coli and S. aureus of 63.5 % and 68.9 %, respectively. Synergistic effects of antibacterial adhesion and contact killing of bacteria contributed to the significant antibacterial performance of the film. The biobased biodegradable film was highly effective in preventing microbial growth when applied as antibacterial food packaging for poultry product, extending the shelf life of fresh chicken breast up to eight days.

Effect of gelatin edible coating with Aronia melanocarpa pomace polyphenols on the cold storage of chilled pork.

In this research, the Aronia melanocarpa pomace polyphenols (AMPPs) were extracted and purified. The purified AMPPs contained the most abundant chlorogenic acid (CGA) at 36.91 mg/100 mg, followed by chrysin at 8.61 mg/100 mg. At a concentration of 60 µg/mL, the purified AMPPs exhibited stronger scavenging activity against: DPPH radical, hydroxyl radical, ABTS∙+, and also showed greater Fe3+ reducing activity than the VC control group. To solve the problem of easy spoilage of chilled meat during storage, gelatin edible coatings containing Aronia melanocarpa pomace polyphenols, referred to as G/AMPPs, were investigated for their effect on the chilled storage of pork. At a 1:1 volume ratio of 1 % polyphenol solution to 3 % gelatin solution, the G/AMPPs coating effectively curbed pH, TVB-N, TVC, drip loss, and b* value increases in chilled pork, while delaying declines in hardness, adhesion, a* value and L* value; The TVB-N content and TVC values demonstrated that the G/AMPPs coating significantly extended the shelf life of chilled pork by up to 15 days. The results showed that G/AMPPs had good preservative, antibacterial and antioxidant effects on chilled pork and thus development of G/AMPPs based coating shows appeared to offer promise for meat preservation.

Enzyme applications in baking: From dough development to shelf-life extension.

Enzymes play a vital role in baking, providing significant benefits from dough development to extending shelf life, which enhances product quality and consistency. Acting as biological catalysts, enzymes such as proteases and amylases break down proteins and starches, modifying dough rheology and improving fermentation. Lipases and oxidases further refine dough texture through emulsification and oxidation, while lipases also produce fatty acid derivatives during fermentation, contributing to the flavor and aroma of baked goods. Xylanases and cellulases optimize dough handling by altering fiber structure, and amylases help maintain moisture and texture, extending the shelf life of baked products. Ensuring regulatory compliance is essential when incorporating enzymes into baking processes, as bakers must address enzyme stability and determine appropriate dosages for reliable outcomes. Ongoing research is exploring innovative enzyme applications, including customized enzyme blends that target specific product qualities, offering new possibilities for product differentiation and innovation. In summary, enzyme-driven advancements present bakers with opportunities to improve product quality, shelf life, and consistency, while meeting industry regulations. This review emphasizes the critical impact enzymes have on dough properties and finished product characteristics, highlighting their role in driving future innovations within the baking industry.

Melatonin treatment maintains the quality properties and storability of carambola fruit by modulating energy metabolism.

The influences of 150 µmol/L melatonin treatment on the quality properties, storability, and energy metabolism in carambola fruit were explored. The results showed that, compared to the control, melatonin treatment significantly retained higher rate of commercially acceptable fruit, and retarded the development of fruit browning and yellowing. Additionally, melatonin treatment displayed higher levels of chromaticity L⁎ and h° values, titratable acid, total soluble solids, total soluble sugars, sucrose, and vitamin C, but lower respiration rate, chromaticity a⁎ and b⁎ values, and reducing sugar content. Moreover, melatonin treatment presented higher levels of ATP, ADP, and energy charge, as well as higher activities of H+-ATPase, Mg2+-ATPase, and Ca2+-ATPase in the membranes of vacuole, mitochondria, and plasma, thereby reducing the damage to cell membranes. These results will provide a scientific basis and practical guidance for melatonin to maintain the quality properties and storability, and to prolong the shelf life of postharvest carambola fruit.

Green Cu particles for functional and biodegradable food packaging solutions.

This study demonstrates a simple approach to synthesize green Cu particles stabilized by poly(n-vinyl)pyrrolidone (PVP): the latter acts as stabilizer and dispersant, and its presence in solution eliminates the need for an inert atmosphere. Synthetic parameters were tuned to obtain particles with diameters >200 nm, to be human-safe and prevent nano-cytotoxicity. PVP and reductant concentrations, with reaction times, were varied to investigate their effect on colloidal stability, kinetics, and particles size. Particles were fully characterized, morphologically and spectroscopically. Cu@PVP colloids were washed, to remove unbound PVP and reactions byproducts, and then embedded in chitosan (CS) polymer matrix, to prepare self-standing films for food packaging applications. Films were obtained by a simple solvent evaporation protocol. Pellicles were characterized by common analytical techniques; viscoelastic properties, water uptake, and Cu2+ ionic release were investigated, as well. The films antimicrobial efficacy was also tested against three different model fungi responsible for agrifood spoilage.

Shelf-life of flavoured olive oil with chili pepper: Comparison between co-milling fresh chili peppers with olives and typical infusion flavouring methods over 18 months of storage.

The aim was to study the shelf-life over 18 months of storage (no light and oxygen exposure) of chili peppers flavoured olive oils comparing flavouring methods of co-milling of fresh chili peppers with sound olives at mill scale with temporary and permanent infusion of dried chili peppers in olive oil. Tocopherols, secoiridoids and capsaicinoids by HPLC-DAD, volatile compounds by HS-SPME-GC-MS, and sensory profiles were studied. The decrease in tocopherols and secoiridoids was greater in "infusion" samples, while a significant increase in capsaicinoids was observed in "permanent infusion" samples. The main changes were observed for sensory and volatile profiles: "infusion" samples were defective already after 2 months with significant increase of defects-relating volatile compounds, while "co-milling" samples were defects-free and characterized by nice balance among hotness/heat and pepper fruity/taste during entire storage. "Co-milling" samples showed better shelf-life (18 months) than infusion ones, and even than EVOO control samples (12 months).

Investigation of in situ and ex situ mode of lactic acid bacteria incorporation and the effect on dough extensibility, bread texture and flavor quality during shelf-life.

Lactococcus lactis subsp. diacetylactis, Lactobacillus delbrueckii subsp. bulgaricus, and Lb. rhamnosus were evaluated for their efficiencies in preserving bread texture and flavor during shelf-life. The investigated LABs exhibited efficiency during preliminary screening in expressing selected enzymes (protease, xylanase, α-amylase, laccase, and glucose oxidase) and producing exopolysaccharide (EPS). Dough samples were supplemented with either sourdough starters containing live LAB cells or LAB cell lysates. Prolonged fermentation further enhanced the protective advantage of sourdough starter incorporation. During the 5-day shelf-life period, in situ enrichment with Lb. rhamnosus led to a mere 12.5-35.4 % hardness change and 13.8-20.7 % overall texture change. Furthermore, sourdough bread with live LAB cell supplementation displayed a more diverse and intense flavor profile, with high concentration of bread key odorants maintained during shelf-life, including 2,3-butanedione, 2-acetyl-1-pyrroline, and 3-methylbutanal. Meanwhile, no significant improvement was found in bread enriched with LAB cell lysates during shelf-life.

Enhancing shelf-life and nutritional value of broccoli florets through vacuum impregnation with calcium chloride and ascorbic acid.

BACKROUND: The present investigation aimed to enhance the postharvest shelf-life of broccoli using vacuum impregnation (VI). Broccoli florets were impregnated with physiologically active chemicals, i.e. calcium chloride and ascorbic acid. Post-impregnation broccoli florets were packed in three different packaging materials (poly(ethylene terephthalate) punnets, low-density polyethylene pouches and shrink-wrap film) and stored at two temperatures (5 and 25 °C). The effects of impregnation solutions, packaging materials and storage temperature on physicochemical attributes (weight loss, total soluble solids, ascorbic acid, total chlorophylls and carotenoid content), antioxidant and phenolic contents, and shelf life were studied. The changes in the chemical structure post-impregnation and during storage were investigated using Fourier transform infrared (FTIR) spectroscopy. RESULTS: Results showed that impregnated broccoli florets exhibited significantly (P < 0.05) higher levels of biochemical attributes immediately after impregnation. During storage, the physicochemical and antioxidant properties of broccoli florets declined for all the samples. However, the reduction in these properties was significantly (P < 0.05) lower in impregnated florets as compared to untreated control samples. Principal component analysis and FTIR results also indicated a clear difference in the impregnated and control samples. The shelf-life of broccoli florets stored at 25 °C was assessed as 4 and 3 days for impregnated and control samples, respectively; whereas the samples stored at 5 °C had a shelf-life of 12 days for impregnated samples and 5 days for the control samples. The findings of the study elucidate the potential of VI in enhancing the initial quality and shelf-life of broccoli. CONCLUSION: The deterioration during storage is primarily due to physiological weight loss, a natural loss of water and volatile compounds that occur following harvest due to transpiration and respiration. Excessive transpiration can lead to dehydration, which reduces the quality and shelf-life of the product. © 2024 Society of Chemical Industry.

Application of Quantitative Magnetic Resonance Imaging (QMRI) to Evaluate the Effectiveness of Ultrasonic Atomization of Water in Truffle Preservation.

Truffles of the Tuber genus (Pezizales, Ascomycetes) are among the most valuable and expensive foods, but their shelf life is limited to 7-10 days when stored at 4 °C. Alternative preservation methods have been proposed to extend their shelf life, though they may alter certain quality parameters. Recently, a hypogeal display case equipped with an ultrasonic humidity system (HDC) was developed, extending the shelf life to 2-3 weeks, depending on the truffle species. This study assesses the efficacy of HDC in preserving Tuber melanosporum and Tuber borchii ascomata over 16 days, using quantitative magnetic resonance imaging (QMRI) to monitor water content and other parameters. Sixteen T. melanosporum and six T. borchii ascomata were stored at 4 °C in an HDC or a static fridge (SF) as controls. QMRI confirmed that T. borchii has a shorter shelf life than T. melanosporum under all conditions. HDC reduced the rate of shrinkage, water, and mass loss in both species. Additionally, the Apparent Diffusion Coefficient (ADC), longitudinal relaxation time (T1), and transverse relaxation time (T2), which reflect molecular changes, decreased more slowly in HDC than SF. QMRI proves useful for studying water-rich samples and assessing truffle preservation technologies. Further optimization of this method for industrial use is needed.

Improving storage duration of tomatoes (Solanum lycopersicum) through electron beam technology.

Electron beam (EB) technology typically consists of high-energy electron streams produced by a linear accelerator. Although promising, the use of EB irradiation as a technique to delay ripening and prevent spoilage in tomatoes has not been extensively investigated. In this study, the effectiveness of EB irradiation in prolonging the shelf life of tomatoes postharvest was investigated. The results indicated that EB irradiation successfully reduced microbial contamination and decay, preserved key quality attributes (such as total soluble solids, titratable acidity, pH, and firmness), and significantly minimized weight loss. Notably, the treatment delayed the biosynthesis of lycopene, a key indicator of ripening, without adversely affecting phenolic content and antioxidant activity, which remained consistent regardless of irradiation. Additionally, different methods for detecting irradiation were evaluated. Thermoluminescence analysis proved to be the most dependable technique, especially for doses exceeding 600 Gy, due to its high sensitivity and specificity. In contrast, photostimulated luminescence and electron spin resonance analyses showed limitations in accurately identifying the irradiation status of foods with high moisture content, such as tomatoes. This study confirms that EB irradiation, while maintaining postharvest quality, extends the shelf life of tomatoes by 5-10 days, suggesting its potential for commercial application in food preservation.

Postharvest Quality of Arugula (Eruca sativa) Microgreens Determined by Microbiological, Physico-Chemical, and Sensory Parameters.

(1) Background: Cultivating microgreens is emerging as an excellent market opportunity. Their easy, short, and sustainable production methods are the main reasons they are approved by growers. However, a feature that still prevents its further spread is the microbiological risk and their rapid senescence. The present study was conducted to evaluate the post-harvest storage and shelf life of arugula microgreens in different packaging through microbiological, physico-chemical, and sensory parameters; (2) Methods: Plants were stored at 5 °C in open air, vacuum sealed, and under modified atmosphere bags and tested at 0, 3, 5, 7, and 10 days; (3) Results: Microgreens stored in all packaging were safe for consumption within ten days. Regarding physical and chemical parameters, open packaging proved to be promising, with less weight loss and slower chlorophyll degradation. The sensory analysis demonstrated that the microgreens stored in the vacuum-sealed packaging showed a decrease in quality from the fifth day onwards for all attributes. However, the MAP presented good scores with a better visual quality, similar to the fresh microgreens.

Research Progress of Machine Learning in Extending and Regulating the Shelf Life of Fruits and Vegetables.

Fruits and vegetables are valued for their flavor and high nutritional content, but their perishability and seasonality present challenges for storage and marketing. To address these, it is essential to accurately monitor their quality and predict shelf life. Unlike traditional methods, machine learning efficiently handles large datasets, identifies complex patterns, and builds predictive models to estimate food shelf life. These models can be continuously refined with new data, improving accuracy and robustness over time. This article discusses key machine learning methods for predicting shelf life and quality control of fruits and vegetables, with a focus on storage conditions, physicochemical properties, and non-destructive testing. It emphasizes advances such as dataset expansion, model optimization, multi-model fusion, and integration of deep learning and non-destructive testing. These developments aim to reduce resource waste, provide theoretical basis and technical guidance for the formation of modern intelligent agricultural supply chains, promote sustainable green development of the food industry, and foster interdisciplinary integration in the field of artificial intelligence.

Review of Bio-Based Biodegradable Polymers: Smart Solutions for Sustainable Food Packaging.

Conventional passive packaging plays a crucial role in food manufacturing by protecting foods from various external influences. Most packaging materials are polymer-based plastics derived from fossil carbon sources, which are favored for their versatility, aesthetic appeal, and cost-effectiveness. However, the extensive use of these materials poses significant environmental challenges due to their fossil-based origins and persistence in the environment. Global plastic consumption for packaging is expected to nearly triple by 2060, exacerbating the ecological crisis. Moreover, globalization has increased access to a diverse range of foods from around the world, heightening the importance of packaging in providing healthier and safer foods with extended shelf life. In response to these challenges, there is a growing shift to eco-friendly active packaging that not only protects but also preserves the authentic qualities of food, surpassing the roles of conventional passive packaging. This article provides a comprehensive review on the viability, benefits, and challenges of implementing bio-based biodegradable polymers in active food packaging, with the dual goals of environmental sustainability and extending food shelf life.

Locust Bean Gum/κ-Carrageenan Film Containing Blueberry or Beetroot Extracts as Intelligent Films to Monitoring Hake (Merluccius merluccius) Freshness.

The main goal of this work was to develop bio-based and ecofriendly intelligent films as freshness indicators to monitor European hake (Merluccius merluccius) quality during storage by using a visual, non-destructive, and real-time technique. Locust bean gum (LBG)/κ-carrageenan (Car) films incorporating blueberry extract (BLE) or beetroot extract (BEE) were developed and their effectiveness to detect hake deterioration during 7 days of storage at 4 °C was evaluated. A visible color response from pink to blue was observed on the BLE films at the end of hake storage, which correlated with the hake deterioration profile, namely an increase in pH values (from 6.60 ± 0.04 to 8.02 ± 0.03), total viable count (TVC, from 4.61 ± 0.36 to 8.61 ± 0.21 log CFU/g), and total volatile basic nitrogen content (TVB-N, from 10.21 ± 1.97 to 66.78 ± 4.81 mg/100 g) beyond the spoilage threshold. The results of this study are very promising, since it was possible to develop a new effective intelligent bio-based responsive indicator film incorporating natural dye BLE, which has the potential to contribute to food waste reduction and improve food safety by detecting the hake freshness status.

Insight into Pelargonium odoratissimum Essential Oil Preservative Properties Effect on Ground Beef.

Pelargonium plants are very popular and well-known for their essential oils (EOs), which are used for medicinal purposes and in food. This study focused on the EO of Pelargonium odoratissimum. First, its composition and antioxidant and antimicrobial activity were evaluated, and finally, its efficacy as a natural preservative in ground beef was tested. The main EO constituents were citronellol (40.0%), nerol (15.3%), and citronellyl formate (12.6%). The antibacterial activity of POEO showed that Enterococcus faecalis ATCC 29212 was the most susceptible strain compared to the other eight strains tested. The antioxidant activity, as measured by the DPPH assay, showed a dose-dependent effect with an IC50 comparable to the standard used, gallic acid. Aerobic plate count, psychotropic bacteria, and Enterobacteriaceae, including Salmonella, were reduced by the addition of Pelargonium odoratissimum essential oils. The oxidative stability was significantly improved compared to the untreated sample. Additionally, the results for metmyoglobin demonstrated a notable preservative effect on sensory properties, including appearance, odor, color, and overall acceptability. The ability to discriminate between all samples and correlate protein and lipid oxidation processes, microbiological characteristics, and sensory measurements was made possible by principal component analysis and heat maps. This research shows the potential benefits of using POEO in the preservation of ground beef by effectively extending shelf life and improving product safety.

Thermoplastic starch/poly(butylene adipate-co-terephthalate) blown film with maltol and ethyl maltol preserving cake quality: Morphology and antimicrobial function.

Maltol (MT) and ethyl maltol (EM) are flavoring compounds that release vapors into headspace, exerting antimicrobial effects and extending food shelf-life. This study investigated biodegradable films for packaged bakery quality. Biodegradable films (40 % polybutylene adipate terephthalate and 60 % thermoplastic starch) were produced via extrusion for films with varying MT and EM contents (1, 3, and 5 %). Scanning electron microscopy revealed smoother and more homogeneous film cross-sections with MT/EM, indicating reduced surface wrinkling. Fourier-transform infrared spectroscopy analysis suggested modified OH and CH stretching due to hydrogen bonding between TPS and EM/MT. The XRD pattern showed sharp MT crystallization, modifying crystal polymorphs of starch and PBAT. EM and MT films exhibited against Staphylococcus aureus after 24 h. Moreover, EM/MT films effectively delayed fungal growth in butter cake, inhibiting mold growth in butter cake more than twofold. These findings suggest that volatile compounds like MT/EM have promising potential for incorporation into PBAT/TPS films, creating active bakery packaging.

Fruit-specific effects of tryptophan and melatonin as active components to extend the functionality of red fruits during post-harvest processing.

Preserving quality attributes in the distribution chain is a challenging task, particularly in fruits with a brief shelf life. The application of melatonin in cherries, raspberries, strawberries and blueberries stored at room temperature was evaluated, as well as the effects of its precursor (tryptophan) to determine their specificity and interchangeable feasibility for post-harvest applications. The results demonstrated that melatonin is effective in all tested fruits, reducing deterioration rate and its severity, preserving fruit firmness and reducing darkening and weight loss. Furthermore, tryptophan applications incremented melatonin contents in strawberries and blueberries and delayed decay in both fruits. Melatonin reduced postharvest losses in all studied fruits related to its antisenescent properties, while the beneficial impact of tryptophan in extending shelf life was fruit-specific and appeared to be partly mediated by melatonin. Melatonin and tryptophan must be considered as active components of new formulations for extending the shelf life of red fruits during post-harvest processing.