Dry Food Research Articles

Effect of different drying techniques on the physicochemical and nutritional properties of Moringa oleifera leaves powder and their application in bakery product

The study analyzed the influence of drying methods and conditions on the quality of moringa leaves powder (MLP) and determined the optimal MLP to wheat flour ratio for cake development. Cabinet drying temperatures enhanced mass and tapped density but reduced the angle of repose, water retention capacity, and oil retention capacity. The moisture content of cabinet-dried MLP samples exhibited a substantial reduction as temperature is increased. The crude protein and fat content increased with increasing drying temperatures. Vacuum dried samples had the highest fiber content (16.62g/100g). Cabinet dried samples at 60°C had the highest ash content (8.37g/100g). The energy obtained from MLP dried in a cabinet at 70°C was the highest (383.33 Kcal/kg). The mineral composition of MLP in vacuum drying showed the largest growth. Sun drying was less efficient in preserving antioxidant components, while vacuum drying was the most successful. But sun drying was more cost effective than that of other drying methods. The composition of cakes formulated from MLP and wheat flour blends exhibited notable variations characterized by an increase in protein content and decrease in carbohydrate content with the incorporation of MLP. 5% and 10% MLP enriched cakes showed the best customer acceptance.

Deciphering Cronobacter sakazakii pathogenicity: Exploring virulence factors and host interactions": A short review

Opportunistic human pathogen called Cronobacter spp. can cause severe illnesses in immunocompromised individuals and newborns. These species are mostly responsible for disorders like meningitis, necrotizing enterocolitis, and bacteremia because they can survive in very dry foods like PIF and have also been identified in various environmental niches, including plants. These species' contamination is ascribed to biofilms, which are biotic or abiotic surface communities. Because they build biofilms on a variety of surfaces, identifying and eliminating them is extremely difficult. For the purpose of creating efficient treatment interventions and preventative measures, it is essential to comprehend the processes of virulence and the relationship between this pathogen and its host. A variety of virulence factors, such as adhesion factors, invasion proteins, biofilm formation components, and secreted toxins, contribute to Cronobacter spp. pathogenicity. Genes involved in capsule formation—such as those involved in exopolysaccharide synthesis—are essential to its pathogenicity because they are critical in desiccation resistance and resistance to host immunological defenses. Furthermore, genes that encode flagella, fimbriae, and outer membrane proteins are linked to host cell adherence and invasion. This review also explores the emerging link between Cronobacter spp. and plants, highlighting the bacterium's ability to survive and persist in the environment because Plants may act as reservoirs, contributing to the contamination of raw agricultural products, which can subsequently enter the food supply chain. Developing focused preventative measures and treatment approaches requires knowledge of the various biological as well as genetic factors that contribute to Cronobacter spp. virulence and how it affects the host. This review clarifies the effects of Cronobacter spp. on the host and investigates the genes linked to virulence in Cronobacter.

Using online projective techniques to understand the consumers’ perception of dry-aged beef

Consumer food preferences are constantly evolving, necessitating research to understand consumer intentions, habits, and attitudes. Dry aging was traditionally used for meat preservation and flavor enhancement. To assess current perceptions, an online questionnaire distributed via social media (snowball sampling) gathered data from 126 consumers. Out of all respondents, 75 % were non-consumers of dry-aged beef. After cluster analysis, the respondents were categorized into two distinct groups: Cluster 1, comprising a higher percentage of consumers (40.3 %), and Cluster 2, characterized by a lower percentage of consumers (11.6 %). Statistical analysis revealed a clear difference in perception before and after trimming the meat. Pre-trim visuals triggered negative associations like “contamination”, “negative feelings” and “spoiled” among consumers of Cluster 2, while post-trimming stimuli elicited positive terms like “flavor” and “tenderness”. Cluster 1 (with a higher proportion of consumers) was primarily motivated by “special occasions”, to buy the dry-aged beef, whereas Cluster 2 was driven by “curiosity” despite “unfamiliarity” with the product. High cost was a significant barrier for consumers of Cluster 1, with 93 % of consumers mentioning it as a negative factor. However, the respondents of Cluster 2 expressed greater concern about unfamiliarity (92 %) and poor pre-trimmed appearance (88 %) compared to Cluster 1. These findings highlight the need for consumer education regarding dry-aged beef’s qualities and advantages, as positive experiences and social influence significantly impact purchasing decisions. Promoting understanding and familiarity with dry-aged beef could significantly broaden its market appeal and consumption.

Techno-Economic Analysis of BAU-STR Dryer for Rice Drying: An Approach to Accelerate Adoption

Postharvest food loss and waste offset worldwide agricultural productivity and food security. Insufficient drying and storage are the prominent drivers of food loss and waste in underdeveloped countries. Mechanical grain drying systems have distinct benefits over sun drying but are inaccessible to underserved communities due to high capital costs and energy demand. This study evaluated the techno-economic and financial performance of a half-ton-capacity BAU-STR dryer. The moisture extraction rate, drying rate, drying efficiency, and energy consumption were used as technical performance indicators. In contrast, the net present value (NPV), internal rate of return (IRR), benefit–cost ratio (BCR), and payback period were considered economic performance indicators. The technical performance analysis results revealed that the moisture content of rice was reduced from 19.5% to 13.5 ± 0.15% in 4.0 h with an average drying rate of 1.5%/h and a drying efficiency of 75.1%. The financial performance analysis resulted in a drying cost, NPV, IRR, BCR, and PBP of USD 0.96 per 100 kg of grain, USD 3018, 135%, 3.0, and 0.73 yr., respectively, when the annual use was 240 h. If the yearly use of the dryer increased from 240 to 720 h, a higher NPV, IRR, and BCR, as well as a lower payback period and drying cost, could be achieved. Adopting a BAU-STR dryer for drying grain (rice and corn) among underserved communities could play a key role in postharvest food loss and waste.

Effect of the Freeze‐Drying Preservation Process on Some Quality Attributes of Pork Meat (Longissimus thoracis)

ABSTRACTMeat preservation processes have been widely studied over time, especially those related to low temperatures (freezing and freeze‐drying); however, there is very little research that directly relates the effect of these processes on the structure of meat—and the main meat proteins—and how these changes affect some attributes of the final quality. Pork loin meat (Longissimus thoracis) was used, which was frozen–thawed and freeze‐dried‐rehydrated to subsequently evaluate changes in its chemical composition and physicochemical parameters such as water activity (aw), pH, and water‐holding capacity. Physical aspects such as color profile, surface myoglobin fraction, shear force, and histological sections were also evaluated, along with thermal analysis by modulated differential scanning calorimetry. The data obtained were analyzed through different statistical techniques. It was found that the freeze‐drying process significantly modifies the interactions of water with the rest of the meat components (p < 0.05), promoting differences concerning samples that were only frozen, allowing us to establish the importance of water and its associations with each other and with proteins on their effect on meat preservation processes at low temperatures.

Quality Characteristics and Essential Oil Properties of Thymus capitatus, Mentha piperita, and Sideritis cypria Dried under Different Conditions

The drying of medicinal and aromatic plants (MAPs) is one of the main preservation methods for these products that can prolong their shelf life, if performed properly. The current study aimed to examine the effects of different drying conditions (sun, shade, and oven drying at 42 °C) on the quality characteristics of Thymus capitatus, Mentha piperita, and Sideritis cypria; their essential oil (EO) yield; and their biological properties (antioxidant and antibacterial activities). According to the results of the current study, oven drying resulted in faster moisture loss for all investigated species and slightly darker products. For T. capitatus, sun drying resulted in higher EO carvacrol content, whereas EOs obtained from shade and oven drying (at 42 °C) presented high total phenolic content and great antimicrobial activity. For M. piperita, shade drying resulted in a higher EO yield and higher iso-menthone content, whilst the EO obtained from oven-dried mint plants presented great antibacterial activity against the investigated foodborne pathogens. S. cypria plants dried in an air-ventilated oven produced an EO rich in β-caryophyllene and α-pinene, which also presented great antioxidant and antibacterial activity. The findings of the current study indicate that traditional drying methods, such as sun and shade, can result in good-quality dried MAPs that can yield EOs with significant biological activities, along with minimum energy consumption and lower carbon dioxide production (lower environmental carbon footprint), as opposed to oven drying. However, the drying-process duration could be a limitation at the industrial scale.

Phytochemical composition, antioxidant activities and anti‐obesity potential of selected vegetables as affected by drying methods

AbstractObesity has reached epidemic statistics worldwide and there is an urgent need to explore more available options in addressing the condition. The potential of vegetables as natural sources of enzyme inhibitors that can regulate the progression of obesity is of great interest particularly due to possible synergistic antioxidant activities. In this study, we evaluated the phytochemical composition, antioxidant activities, and in vitro enzyme inhibition properties of selected vegetables as influenced by sun and cabinet drying methods. While a significant increase was observed in the phytochemical composition of most of the vegetables, the two drying methods had varying effects on all parameters. Cabinet drying yielded higher saponin (2.86–4.67 mg/100 g), phenolics (19.30–57.02 mg/100 g), and alkaloids (31.58–37.61 mg/100 g) contents while sun drying gave better results for flavonoids (88.13–234.15 mg/100 g). The DPPH (11.45%–29.61%) and ABTS (22.70%–35.48%) antioxidant activities varied significantly. Cabinet‐dried cabbage and sun dried carrot flours displayed the highest inhibition against alpha amylase and pancreatic lipase, respectively. A strong positive correlation was observed between phenolics and amylase inhibition and also between saponin and pancreatic lipase inhibition. Consequently, vegetable flours could serve as versatile products for the therapeutic management of obesity and related diseases.

The significant relief of Ayurvedic management for Severe Migraine Episodes: A Case Study

Migraine is a common and debilitating neurological disorder marked by recurrent, severe headaches that are frequently accompanied by nausea, sensitivity to light, and sensitivity to sound. These migraine attacks can profoundly disrupt daily life and overall well-being. The development of migraines is influenced by a complex interaction of genetic, environmental, and neurovascular factors. Recent studies have enhanced our understanding of migraine mechanisms, highlighting the role of cortical spreading depression and neuropeptides such as calcitonin gene-related peptide (CGRP). Managing migraines effectively often involves a combination of lifestyle changes, medications, and, in some cases, alternative treatments. In Ayurveda, migraine is compared with Ardhavbhedaka (half-headache) which belongs to the Shiroroga. Ardhavbhedaka is primarily associated with imbalances in the Pitta and Vata Doshas due to etiological factors such as eating dry food, eating immediately after a meal, exposure to air from the east, dew, excessive sexual activity, preventing the natural urge of bodily waste, excessive physical labor, develop Ardhavbhedaka.

Impacts of Five Different Drying Methods on Volatile Organic Compounds in Mulberry Fruits.

The mulberry fruit is edible and medicinal, and it is commonly referred to as the "best health product of the 21st century". The purpose of this study was to find out whether different drying methods affect the quality of mulberry fruits and the main nature of the volatile organic compounds (VOCs) they contain. This study used vacuum freeze-drying (VFD), vacuum drying (VD), sun drying (SD), hot-air drying (HAD), and microwave drying (MD) to treat fresh mulberry fruits. Gas-phase ion mobility spectrometry (GC-IMS) was used to detect and analyze the VOCs in mulberry fruit samples treated with the different drying methods. There were 47 VOCs detected, with aldehydes and alcohols dominating. The obtained data were subjected to principal component analysis (PCA), cluster analysis (CA), nearest neighbor fingerprint analysis, and partial least-squares regression analysis (PLS-DA). The conclusion was drawn that fresh mulberry fruits contain abundant VOCs, and mulberry fruits after VD contain many aldehydes; thus, VD promoted the synthesis of phellandrene and other compounds widely used in the preparation of cosmetics such as perfume and soap. HAD promoted the synthesis of esters commonly used in the preparation of fruit flavor and wine essence. The higher (E)-2-heptenal content with SD was conducive to the Maillard reaction. MD promoted the synthesis of heptanal and valeraldehyde with aroma characteristics such as fatty, green, fruity, grassy, and floral. According to the VIP results, VOCs (E)-2-heptenal, pentanal D, cyclohexanone, and 2-hexanone D influenced the VOCs in most of the mulberry fruit samples. The findings of this study provide an important reference for drying mulberry fruits, which, in turn, will help to ensure the safety and effectiveness of processed mulberry fruit products.

Individual and combined occurrences of the prevalent mycotoxins in commercial feline and canine food.

Mycotoxins, such as aflatoxin B1 (AFB1), deoxynivalenol (DON), fumonisins (FBs), ochratoxin A (OTA), T-2 toxin (T-2), and zearalenone (ZEN), can contaminate animal feeds and pose risks to animal health and production performance. These mycotoxins are commonly found in cereals and grains, with the increased use of cereals in pet food, there is a rising concern about mycotoxin contamination among pet owners. To address this, we analyzed imported brands of feline and canine food from the Chinese market produced in 2021-2022. Ninety-three samples were analyzed, comprising 45 feline food and 48 canine food samples. Among them, 14 were canned food and 79 were dry food. The results indicate that AFB1, DON, FBs, OTA, T-2, and ZEN occurred in 32.26%, 98.92%, 22.58%, 73.12%, 55.91%, and 7.53% of the samples, respectively. The most prevalent mycotoxin was DON, followed by OTA, T-2, AFB1, and FBs, whereas ZEN was less frequently detected. The mean concentrations of the six mycotoxins in pet feed samples were 3.17μg/kg for AFB1, 0.65mg/kg for DON, 2.15mg/kg for FBs, 6.27μg/kg for OTA, 20.00μg/kg for T-2, and 30.00μg/kg for ZEN. The levels of mycotoxins were generally below the limits of the Pet Feed Hygiene Regulations of China and the EU. Notably, a substantial majority of the pet food samples (88 out of 93) were contaminated by two or more mycotoxins. AFB1, FBs, OTA, and ZEN occurred slightly more often in feline food than in canine food. Except for OTA, the contamination rates for the other five mycotoxins in canned food were lower than those in dry food. Moreover, except for AFB1, the levels of the other five mycotoxins in canned foods were lower than those in dry foods. This study highlights the widespread contamination of pet foods with mycotoxins, which poses a significant risk to pets from continuous exposure to multiple mycotoxins.

Moderate-intensity training can ameliorate the process of cardiac apoptosis induced by lithium drug consumption in male Wistar rats

Background and objectiveLithium medication, given its significant role in the treatment or reduction of psychiatric disorders, may exert adverse effects on cardiac tissue. Therefore, this study aimed to investigate the effects of different exercise training intensities on the process of cardiac apoptosis and serum levels of cardiac troponin I (cTnI) resulting from lithium administration in male Wistar rats. MethodologyIn the present experimental study, 35 male Wistar rats were randomly divided into five groups (n=7); Control (CTL), Lithium (Li), High-Intensity training + lithium (HIT-Li), Moderate-Intensity training + lithium (MIT-Li), and Low-Intensity training + lithium (LIT-Li). Lithium drug (dose of 40mmol/kg dry food weight) and exercise training (5 days per week) were administered for eight weeks. Serum levels of cTnI, mRNA expression of Bcl-2, Bax, and Caspase-3, and histopatholigical changes were assessed by using the ELISA method, Real-Time PCR, and H&E staining, respectively. ResultsThe expression of the Bcl-2 gene was significantly increased in the LIT-Li group compared to the Li group (P = 0.003). Serum levels of cTnI were considereably higher in the Li group compared to the MIT-Li group (P = 0.0001). The expression of the Bax gene, in the LIT-Li, HIT-L, and Li groups, significantly increased compared to the MIT-Li group (P = 0.0001). Histopathological scores decreased in MIT-Li compared to Li group (P = 0.001). ConclusionIt seems that among different exercise intensities, the greatest protective effect against lithium consumption can be observed with moderate exercise intensity, which may potentially modulate factors influencing cardiac apoptosis and reduce lithium toxicity in the cardiac tissue of rats.

Investigation of thermodynamics performance of solar dryer equipped with double pass flat, v-corrugated, and low-e coated collectors

In this study, a solar dryer incorporating a flat plate heat exchanger to recover heat from exhaust air was investigated to explore the usability of different types of collectors in the system. Their usability was further evaluated through economic and environmental analyses. Moreover, the thermodynamic performance of the solar dryers was evaluated under two weather conditions in Nepal. Apple drying experiments were conducted for 8 hours from 09:00 to 17:00 from February to April 2023 on solar dryers and with open sun drying (OSD) in Dhulikhel, Nepal. The results showed that the low emissivity (low-e) coated aluminum collector was more efficient in terms of collector efficiency and drying rate than collectors with flat or v-corrugated GI absorbers. The average collector efficiency and drying rate were found to be 89% and 107 g/(h×m2) using the low-e coated aluminum collectors, while the values were 50% and 84 g/(h×m2) for the GI sheet collector. The results indicated a slight improvement in the performance of v-corrugated collectors, with values of 53% and 89 g/(h×m2). The drying rate for OSD was found to be 78 g/(h×m2), which was lower than for the dryers with all collectors used in this study. In terms of economic analysis, the dryer equipped with the low-e coated collector was found to be superior, with a payback time of 1.61 years compared to the dryers with flat or v-corrugated GI collectors. Reducing the thermal losses due to radiation by using the low-e coated absorber was shown to be more important than increasing the absorber area using v-corrugated GI sheets.

Performance investigation of newly developed novel hemispherical solar dryer for sustainable food preservation: Comparative analysis with traditional methods

To preserve the world’s food resources, drying agricultural products is crucial for prolonging their shelf life. A novel concept of 1.5 m hemispherical solar dryer surmounts the limitations of conventional dryers like long drying time, solar tracking, large space requirement etc. Trials were performed on Thomson grapes to convert into raisins. For the purpose of fair accuracy in comparison, experiments were conducted on hemispherical solar dryer (active and passive mode), traditional cabinet solar dryer as well as open sun drying (OSD) by maintaining the uniform test conditions. An average moisture removal rate of 0.1935096 kg/h was obtained in hemispherical dryer. The hemispherical solar dryer significantly reduced drying time for converging grapes into raisins to 13 days, compared to 18 days in a cabinet solar dryer and 19 days with OSD. The hemispherical dryer, through a gap, creates a greenhouse effect, reaching a 70.1 °C maximum temperature and an average of 60.7 °C at 796 W/m2 average solar energy. The hemispherical dryer attained a drying efficiency of 5.67 %. Six mathematical models were employed for hemispherical and cabinet dryers. Amongst these Two term and Wang & Singh models were found suitable for the experimental data and provided precise prediction of moisture ratio.

Utilizing superheated steam to inactivate Enterococcus faecium NRRL B-2354 on various material surfaces used in food and produce industries

Traditional sanitation in dry food and produce manufacturing plants is challenging as residual moisture can harbor microbial contamination. Superheated steam (SHS) is produced when water is heated to temperatures (125–400 °C) beyond the boiling point. SHS does not lead to condensation on surfaces. There are limited studies available on the sanitation efficacy of SHS on different surfaces. This study was conducted to understand the sanitation efficacy of SHS to inactivate Enterococcus faecium NRRL B-2354 on different surfaces (stainless steel, concrete, plywood, leather, polytetrafluoroethylene (PTFE), silicon rubber, cotton, and cardboard). The surfaces were either spot inoculated or coated with a representative food matrix (baby formula) and treated with SHS at 150 °C for a total process time (come-up time + treatment time) of 3 min. Spot-inoculated surfaces showed a higher microbial inactivation (range: 9.2 ± 0.9 to 10.7 ± 0.7 log reduction/coupon) whereas surfaces with inoculum coated with baby formula had lower microbial inactivation (range: 7.8 ± 0.4 to 9.6 ± 0.4 log reduction/coupon). The effects of surface characteristics like thermal inertia, surface roughness, and hydrophobicity of microbial inactivation were studied. Prolonged usage of SHS (150 °C for 5 min once a week over 8 weeks) did not alter surface characteristics, particularly roughness of stainless steel, silicone rubber and plywood.

Improving functional properties of starch-based films by ultraviolet (UV-C) technology: Characterization and application on minced meat packaging

This study aimed to utilize UV-C technology to improve the functional properties of starch-based films for minced meat packaging. Starch film solutions were exposed to UV-C light for varying durations (15, 30, 60, and 120 min). Results revealed significant reductions in the water solubility, swelling degree, and elongation at break values of films following treatment (P < 0.05). Opacity values consistently increased with prolonged UV exposure time, particularly in films treated for 30, 60, and 120 min (P < 0.05). Also, the water contact angle of films significantly increased (P < 0.05) while their water vapor permeability decreased. SEM observations showed that UV-C treatment resulted in excellent miscibility, compatibility, and strong intermolecular bonding in starch films. FTIR, X-ray diffraction, and thermogravimetric analysis further confirmed the excellent compatibility of UV-C-treated films within the film matrix. Notably, starch films treated with UV-C for 60 min exhibited the best characteristics for minced meat packaging. Minced meat packaged with these treated films showed lower thiobarbituric acid values (0.033 mg MDA/kg sample) and total viable counts (5.93 log CFU/g) than those packaged with untreated films throughout storage. These findings highlight the significant potential of UV-C-treated starch-based films, particularly those treated for 60 min, as functional packaging solutions for minced meat preservation.

Bioassays of Fumigant Toxicity and Repulsiveness of Haplophyllum tuberculatum Extracts

Abstract Food grains were severely damaged by stored goods insects. The red flour beetle Tribolium castaneum, the cigarette beetle Lasioderma serricorne and the rice weevil Sitophilus orysae are some of the most destructive pests which attack raw cereals throughout the world. In stored grain mill, fumigation with synthetic fumigants was the most economical tool for managing stored pests. Nevertheless, the application of chemical pesticides caused adverse effects on humans and environment. Chloroform, acetone, methanol and water extracts and essential oil of Haplophyllum tuberculatum aerial parts were tested for their fumigant and repellent effect against adults of the three stored products pests (T. castaneum, L. serricorne and S. oryzae). GC/MS analysis of the essential oil resulted in determination of 19 compounds. The major constituents were β-phellandrene (16.17%), trans-p-menth-2-ene-1-ol, (13.22%) and cis-p-menth-2-ene-1-ol (8.29%). Thus, it seemed that the essential oil had the highest fumigant activity against L. serricorne after 12 h of exposure compared to the two other insects with a LC50 equal to 38.59 µ.l-1 air. The best repellency was observed for the chloroform and methanol extracts against T. castaneum. The respective repellent doses RD50 values were = 0.03 and 0.04 mg.ml-1 after 24 h of exposure. However, after 24 h of exposure acetone extract seems to be more repellent with respective repellent dose values of = 0.14 mg.ml-1 (RD50) against L. serricorne. H. tuberculatum essential oil and extract proved to be effective in control pest infestations in grains and dry food products.

Development of a top-lit-up-draft biomass gasifier as a sustainable heat source for effective drying of plantain slices in a cabinet dryer

This paper explored the development of a top-lit-up-draft biomass gasifier as a sustainable heat energy alternative to the traditional sun drying and the costly, unreliable heat energy sources such as grid-electricity and petrochemical fuels commonly used for cabinet dryers, especially in developing countries like Nigeria. The gasifier utilized the principle of top-lit-updraft biomass gasification system to thermochemically converts agricultural residues into clean heat energy. The designed gasifier has reactor diameter and height of 28cm and 90cm, fuel consumption rate of 55kg/hr, gasification airflow rate of 82.1m3/hr, DC fan motor of 15W, equipped with 30Ah battery power source, and capable of supplying heat energy of 260.16MJ/h. Performance testing using input variables of fuel loading (10kg-20kg), fan speed (4000rpm-6000rpm), and fuel type (palm-kernel shell, coconut shell, coconut husk, and wood shavings) assessed the gasifier responses such as fuel gasification time, flame temperature, thermal and combustion efficiencies, and carbon monoxide (CO) emission of the flame. Results revealed maximum thermal efficiency, peak flame temperature and longest gasification time of 86.02%, 8750C, and 130min respectively, when operated with palm-kernel shell at maximum fan speed and fuel loading, which emitted average CO of 1ppm lower than the least international air pollutant threshold of 9ppm. Highest combustion efficiency of 99.9% was attained using wood shavings at maximum fan speed and fuel loading. The results highlighted the potential of the gasifier as an effective heat source for drying applications, particularly for drying plantain slices in a cabinet dryer.

Development of polycaprolactone-based electrospun nanofiber incorporated lemon beebrush essential oil-loaded metal-organic frameworks as a novel active food packaging for meat preservation

This research involved the development of novel antimicrobial and antioxidant food packaging using electrospun nanofibrous films (ENFs) made of polycaprolactone (PCL) with added lemon beebrush (Aloysia Citriodora) essential oil (LEO)–loaded chromium(III)-metal–organic framework (Cr(III)-MOF) to extend the shelf life of red meat. We conducted a comprehensive range of microstructure, physical, and mechanical tests on nanofibers based on PCL. The PCL/LEO@Cr(III)-MOF nanofibers displayed improved thermal stability, anti-deformation capacity, and increased TS (62.3–68.2 MPa) but reduced flexibility (32.6–28.2 %). Moreover, the inclusion of LEO@Cr(III)-MOF led to a decreased hydrophobic surface due to the formation of hydrogen bonds, as well as a reduction in the water vapor barrier (2.8–2.2 × 10−11 g m/m2. s. Pa). Additionally, the PCL/LEO@Cr(III)-MOF nanofibers exhibited antibacterial (E. coli (20.3 mm) and S. aureus (24.3 mm)) and antioxidant (DPPH and ABTS) activity. The effectiveness of PCL-based nanofibers was evaluated in red meat samples stored at a temperature of 4 °C, and the findings demonstrated that PCL/LEO@Cr(III)-MOF nanofibers preserved the chemical (pH, TVB-N, PV, and TBA) and microbial quality (PTC and TVC) of the samples and prolonged their shelf life by 18 days. These findings indicate the promising potential of the developed PCL/LEO@Cr(III)-MOF electrospun nanofibers for active food packaging.

Energy, exergy, exergo-economic and exergo-environmental analysis of waste heat-based convective dryer

Food drying is a widely used method of food preservation worldwide, and the utilization of waste heat from exhaust flue gas presents a significant opportunity to reduce the energy consumption of industrial drying processes. This study thoroughly examines the energy and exergy efficiency, sustainability indicators, and various exergo-environmental and exergo-economic parameters to assess the performance of a waste heat-based convective dryer (WHCD). The study found that drying at 70 °C performed the best (among 50 °C, 60 °C and 70 °C) for the overall drying process, with a maximum overall exergetic efficiency of 4.89 %. The results of exergo-economic analysis revealed that the drying chamber exhibited the highest exergy destruction cost at US$0.01193 per hour, and it was determined that improving the drying chamber was of paramount importance. An exergo-environmental assessment indicates that the proposed dryer effectively mitigates 14.15 tons of CO2 over a 20-year lifespan. Sensitivity analysis of the proposed system reveals that the energy efficiency is more sensitive to the food drying temperature than the exergy efficiency. A 33 % increase in drying temperature increases the exergy efficiency by 19.37 % while reducing the energy efficiency by 37.54 %. Hence, adopting the proposed system in industrial settings could significantly enhance energy-efficient and sustainable food drying processes.

Effect of surface charge on mechano-bactericidal activity of cellulose nanocrystals constructed chevaux-de-frise and meat preservation

The nanostructured insect wings have inspired the development of antimicrobial surfaces with mechano-bactericidal activity. For the first time, a chevaux-de-frise-like nanostructure was fabricated through the coating of cellulose nanocrystals (CNC) onto regenerated cellulose (RC) films via vacuum filtration and the impact of contact time, temperature, and surface topography on eliminating foodborne bacteria was examined. Herein, our focus is to explore in more detail how the surface charge of CNC affects the mechano-bactericidal activity and the performance of chevaux-de-frise-like nanostructure in meat preservation. CNC with neutral (weak), negative, and positive charges were prepared by hydrochloric acid hydrolysis (HCNC), TEMPO oxidation (TCNC), and amination (ACNC), respectively, and showed similar reinforcing effects on the tensile strength (increased from 74.23 ± 1.20 to about 100 MPa) and water vapor barrier property (reduced from 1.83 ± 0.08 to about 1.20 × 10−7 g m−1 h−1 Pa−1). Among them, RC-ACNC showed the highest log reduction against Escherichia coli (0.83 ± 0.06) and Staphylococcus aureus (0.69 ± 0.04) after 5 min contact, respectively, indicating the important role of attractive force in fast eliminating bacteria upon contact. It was worth noting that, during the meat preservation test, all three CNC-coated RC films exhibited a similar 0.4 log reduction of bacteria after day 4, likely due to the same physical attachment with an extended contact time. Therefore, the construction of chevaux-de-frise nanostructure from CNC on food packaging provides a sustainable strategy to contribute to preventing bacterial growth.