Potential role of exogenous melatonin involved in postharvest quality maintenance of Vitis labrusca × vinifera 'Kyoho'.

BACKGROUND: Melatonin is an endogenous free radical scavenger with antioxidant activity that preserves the commercial value of postharvest fruits and delays fruit senescence. To explore the effect of exogenous melatonin on antioxidants and aroma volatile compounds of grapes (Vitis labrusca × vinifera 'Kyoho'), the grapes were treated with distilled water (control), 50 µmol L-1 of melatonin (M50), and 100 µmol L-1 of melatonin (M100) for 30 min and were then stored at 4 °C for 25 days. RESULTS: Exogenous melatonin decreased the rachis browning index, the decay development, the weight loss rate, the berry abscission rate, and the respiration rate, promoted the accumulation of total phenolics and total flavonoids, and delayed the reduction of anthocyanins and total soluble solids. In volatile compounds, the accumulation of esters, aldehydes, and alcohols in grapes was promoted, and the terpenes content was reduced by exogenous melatonin. CONCLUSION: Exogenous melatonin had potentially positive effects on the postharvest life and quality maintenance of grapes. These findings provide theoretical support for the application of melatonin in grape storage and preservation. © 2023 Society of Chemical Industry.

Goat milk powder supplemented with branched-chain fatty acid: influence on quality and microstructure.

BACKGROUND: Branched-chain fatty acid (BCFA) is effective in preventing and helping to treat neonatal necrotizing enterocolitis. It is essential to supplement goat-milk powder for formula-fed preterm infants with BCFA. In this study, the quality and microstructures of milk powders supplemented with different concentrations of BCFA were evaluated, using goat milk powder without BCFA as the control group (CG). RESULTS: In comparison with the CG, goat milk powder supplemented with BCFA exhibited smaller fat globules and a significant drop in overall particle size. During 16 weeks of storage, BCFA-supplemented groups showed suitable moisture content and viscosity and good solubility. The BCFA also helped reduce the number of folds on the surface of the milk powder particles. CONCLUSION: The findings of this study indicate that goat milk powders with BCFA exhibit differences in quality and microstructure in comparison with ordinary goat milk powder, which is relevant for the future development and application of BCFA in foods. © 2022 Society of Chemical Industry.

Washing of residues from the circular economy prior to sustainable landfill: Effects on long-term impacts.

Sustainable landfill continues to play a fundamental role in closing the loop of residual materials of the circular economy. The sustainable landfill relies on both pretreatments and in situ treatments to stabilize the residual waste and immobilize the contaminants, achieving the final storage quality (FSQ) within one generation (typically 30 years). The aim of the study was to investigate the efficiency of the waste washing pretreatment in reducing the waste leaching fraction prior to landfilling, and in decreasing the time needed to reach the FSQ. A laboratory scale washing test was performed on three different kinds of residues from municipal solid waste treatment, usually landfilled: residues sieved from separately collected bio-waste (RB); residues sieved from compost (RC); and residues sieved from mixed waste treatment-plastic line (RP). Column landfill simulation tests were performed to predict and compare the landfill long-term emissions of both washed and raw residues. The results revealed that the washing pretreatment significantly reduced the leachable fraction of contaminants, decreasing the time needed to reach the chemical oxygen demand and ammonia FSQ limits. However, RP residue was the only one respecting the FSQ limits within 30 years.

Effects of different drying methods on the storage stability of barley grass powder.

BACKGROUND: Barley grass (BG) powder has gradually attracted researchers' attention for its abundant nutritional components and functional activity. Yet, the effect of different drying methods on storage stability is still unclear. In this study, BG was subjected to hot-air drying (HAD), steam blanching prior to hot-air drying (SHAD), vacuum freeze drying (VFD), and far-infrared drying (FID). Effects of different drying methods on BG powder during storage were evaluated. RESULTS: Moisture content of dried samples during storage decreased at 50 °C, but at 37 °C increased first and then remained stable. The a* value of SHAD BG powder before storage was the highest (-6.51), followed by FID, HAD and VFD. Moreover, the a* value increased during the storage process. Contents of l-ascorbic acid and total chlorophyll in samples dried by VFD were 28.29 and 7.8 g kg-1 , respectively. The degradation of chlorophyll a and b followed a first-order kinetics model and was modeled by the Arrhenius equation. The activation energies for chlorophyll a were 83.68, 83.21, 62.29 and 76.64 kJ mol-1 in BG powder dried by SHAD, FID, VFD and HAD, respectively. The activation energies for chlorophyll b were 66.76, 48.03, 61.02 and 58.01 kJ mol-1 in SHAD, FID, VFD and HAD BG powder, respectively. CONCLUSION: VFD had the highest preservation of color, l-ascorbic acid and chlorophyll compared to HAD, SHAD and FID. SHAD shortened the drying time and delayed the degradation of l-ascorbic acid and chlorophyll during storage. © 2021 Society of Chemical Industry.

Transcriptomics Reveals the ERF2-bHLH2-CML5 Module Responses to H2S and ROS in Postharvest Calcium Deficiency Apples.

Calcium deficiency usually causes accelerated quality deterioration in postharvest fruit, whereas the underlining mechanism is still unclear. Here, we report that calcium deficiency induced the development of bitter pit on the surface of apple peels compared with the healthy appearance in control apples during postharvest storage. Physiological analysis indicates that calcium-deficient peels contained higher levels of superoxide anion (O2•-), malondialdehyde (MDA), total phenol, flavonoid contents and polyphenol oxidase (PPO) activity, and reduced calcium, H2S production, anthocyanin, soluble protein content, and peroxidase (POD) activity compared with those in calcium-sufficient peels. The principal component analysis (PCA) results show that calcium content, ROS, and H2S production were the main factors between calcium-deficient and calcium-sufficient apple peels. Transcriptome data indicated that four calmodulin-like proteins (CMLs), seven AP2/ERFs, and three bHLHs transcripts were significantly differentially expressed in calcium-deficient apple peels. RT-qPCR and correlation analyses further revealed that CML5 expression was significantly positively correlated with the expression of ERF2/17, bHLH2, and H2S production related genes. In addition, transcriptional co-activation of CML5 by ERF2 and bHLH2 was demonstrated by apple transient expression assays and dual-luciferase reporter system experiments. Therefore, these findings provide a basis for studying the molecular mechanism of postharvest quality decline in calcium-deficient apples and the potential interaction between Ca2+ and endogenous H2S.

Effect of bound water on the quality of dried Lentinus edodes during storage.

BACKGROUND: Water absorption is the dominant factor affecting the quality deterioration of dried Lentinus edodes. We therefore analyzed the effect of moisture content and dynamic water status on physical properties of the mushroom stored at water activity (aw ), 0.33, 0.43, 0.67, 0.76, and 0.84 for 50 days. Moisture mobility and water status were analyzed using low-field nuclear magnetic resonance, while hardness and microstructure were determined as texture characteristics. Meanwhile, an electronic nose and headspace solid-phase micro-extraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS) were used to analyze the flavor properties of dried L. edodes. RESULTS: The results showed that bound water was the dominant water status in dried L. edodes. The content and molecular mobility of bound water increased at aw = 0.67, 0.76, and 0.84. This contributed to discoloration, hardness loss, and microstructure sparsity of dried L. edodes. The increasing content and molecular mobility of bound water aggravated the deterioration of characteristic flavor by reducing acid, aldehyde, and ketone content. CONCLUSION: Unlike immobilized or free water, bound water had a critical influence on the quality deterioration of dried L. edodes during storage. © 2019 Society of Chemical Industry.

Cooperative effects of slight acidic electrolyzed water combined with calcium sources on tissue calcium content, quality attributes, and bioactive compounds of 'Jiancui' jujube.

BACKGROUND: Slight acidic electrolyzed water (SAEW) has been widely used in cleaning systems of fruit and vegetables. It strongly reduces microbial contamination. However, no information is available on whether SAEW offers the potential for fresh jujube cleaning. The purposes of this study were, first, to compare the effectiveness of SAEW with commercial sanitizers (i.e. sodium hypochlorite (NaClO) or calcium hypochlorite (Ca(ClO)2 )) on 'Jiancui' jujube; second, to determine the response of fruit decay, tissue calcium (Ca) content, and quality attributes to dip application of calcium nitrate (Ca(NO3 )2 ) by concentration; and third, to investigate the effects of SAEW combined with Ca(NO3 )2 or calcium acetate (Ca(OAc)2 )) on fruit Ca uptake, quality attributes, and bioactive compounds. RESULTS: Fruits washed with NaClO, Ca(ClO)2 , or an SAEW solution showed no difference in reduction of decay incidence. In contrast to NaClO treatment, SAEW or Ca(ClO)2 significantly retarded losses in fruit firmness (FF), green color (hue angle), and skin lightness (L*), and maintained intact pericarp tissue structure during storage at 1 °C. Application of Ca(NO3 )2 at 5-10 g L-1 effectively promoted Ca2+ uptake and minimized declines in FF and L* value but had no effect on decay development. Adding 10 g L-1 Ca(NO3 )2 or Ca(OAc)2 to SAEW provided an additional benefit in increasing decay resistance, increasing Ca2+ into fruit and increasing levels of bioactive compounds in jujube fruit. CONCLUSION: SAEW in combination with Ca(NO3 )2 or Ca(OAc)2 has commercial potential for fresh jujube disinfection and improving storage quality as a result of the cleaning processes. © 2019 Society of Chemical Industry.

Dog food production using curcumin as antioxidant: effects of intake on animal growth, health and feed conservation.

The objectives of this study were to produce dog food containing curcumin replacing synthetic antioxidants, to evaluate its beneficial effects on animal growth and health. Curcumin (100 mg/kg) was added after the extrusion process along with the other micronutrients. The final concentration of curcumin was 32.9 mg/kg. The control feed was composed of the same ingredients without curcumin. After a storage of 6 months, feed composition and pH did not differ; however, the feed with curcumin showed lower protein oxidation, lipid peroxidation and higher total antioxidant capacity. After 2 months of feed production, 12 young Beagle dogs received either curcumin-containing food (n = 6)  or the control diet (n = 6). The animals were fed twice a day using individual kennels. Blood samples were taken on d 1, 35 and 42. During the first 30 d of the study, the animals had natural infectious diseases that were controlled with anti-protozoals and antibiotics. Greater numbers of red blood cells were observed in dogs fed with curcumin (d 35 and 45), and there were greater numbers of white blood cells as a consequence of increased neutrophils on d 42. At the end of the experiment, a significant reduction in the number of lymphocytes was observed in dogs that ingested curcumin (d 42), suggesting an anti-inflammatory effect, manifested as a decrease in globulin levels. In the final 15 d of the experiment, the animals were clinical healthy. Higher serum levels of glucose, urea, triglycerides and cholesterol were observed in dogs fed with curcumin. Curcumin increased the activity of several antioxidant enzymes in addition to non-protein thiols and the total antioxidant capacity in the serum, consequently reducing levels of oxygen reactive species. Curcumin supplementation of dogs did not favour growth or weight gain. Neverthless, it was concluded that curcumin improved animal health, with emphasis on the stimulation of the antioxidant system and evidence of an anti-inflammatory effect.

Effect of PLA/PBAT Antibacterial Film on Storage Quality of Passion Fruit during the Shelf-Life.

In this experiment, we studied the effect of poly(lactic acid)/poly(butylene adipate-co-terephthalate) (PLA/PBAT) blend films on the efficiency of passion fruit preservation at 20 °C. The weight loss, shrinkage index, firmness, and total sugar of passion fruit packaged with PLA/PBAT films had no significant differences compared with PE films during 21 days (p > 0.05). PLA/PBAT films can more effectively reduce the rising of ethanol content and delay the total acid, ascorbic acid, and sensory evaluation. Compared with unpackaged (CK) and polyethylene (PE) films, PLA/PBAT films are more conducive to preserve the overall flavor of passion fruit during storage time, in agreement with sensory evaluation, tested by E-nose, E-tongue, and GC-MS, which also proved that it can effectively maintain the edible quality of passion fruit during storage time. We believe that our study makes a significant contribution to literature because it paves the way to the generalization and application of packaging films based on composite antibacterial polymers and facilitates the commercialization of fresh passion fruit as an important health food.

Curcumin-Based Photodynamic Sterilization for Preservation of Fresh-Cut Hami Melon.

Fresh-cut fruits and vegetables are the main sources of foodborne illness outbreaks with implicated pathogens such as Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes. This study aimed at investigating the influence of two key parameters (concentration of curcumin and illumination time) on the effects of curcumin-based photodynamic sterilization on the preservation of fresh-cut Hami melons. The results indicated that illumination with 50 µmol/L curcumin for 60 min using a blue LED lamp reduced the total aerobic microorganism count by ~1.8 log CFU/g in fresh-cut Hami melons. Besides this, the effects of photodynamic sterilization on the soluble solids content, color, water content, firmness, and sensory indices of the fresh-cut Hami melons were also evaluated. Compared to the control group, photodynamic sterilization can effectively delay the browning rate and maintain the luminosity, firmness, water content, and soluble solids content of fresh-cut Hami melon. The sensory quality was indeed preserved well after 9 days of storage in a fridge. These results showed that photodynamic sterilization is an effective and promising technology to prolong the shelf life of fresh-cut Hami melons.

Effect of carbon dots with chitosan coating on microorganisms and storage quality of modified-atmosphere-packaged fresh-cut cucumber.

BACKGROUND: In order to inhibit microorganisms and improve storage quality of fresh-cut cucumber, fresh-cut cucumber was treated by carbon dots (CDs) from kelp/chitosan (CH) coating solution with CD concentrations of 0%, 1.5%, 3% and 4.5% and then packaged as well as stored at 4 °C for 15 days. The effect of CDs/CH coating on microorganisms and the quality of modified-atmosphere-packaged fresh-cut cucumber during storage were investigated. RESULTS: The CDs was monodispersed spherical morphology with size distribution of 0.54-0.83 nm. Interaction of CDs and CH had the generation of strong hydrogen bond. Inhibition zone diameters of CDs/CH coating against Staphylococcus aureus and Escherichia coli were enhanced with the increase of CD concentrations. Moreover, CDs/CH coating inhibited the growth of total number of colonies, mold, and yeast in modified-atmosphere-packaged fresh-cut cucumber during storage. A coating of 4.5% CDs/CH effectively reduced the losses of weight, firmness, and total soluble solids, the degradation of ascorbic acid content and flavor, and inhibited peroxidases activity, as well as decreased water mobility in fresh-cut cucumber during storage. CONCLUSION: The results indicated that a CDs/CH coating was helpful for inhibiting microorganisms and improving storage quality, and could be an effective method to prolong shelf life of fresh-cut cucumber. © 2019 Society of Chemical Industry.

Transient heat stress during tuber development alters post-harvest carbohydrate composition and decreases processing quality of chipping potatoes.

BACKGROUND: Adverse air and soil temperatures are abiotic stresses that occur frequently and vary widely in duration and magnitude. Heat stress limits productivity of cool-weather crops such as potato (Solanum tuberosum) and may degrade crop quality. Stem-end chip defect is a localized discoloration of potato chips that adversely affects finished chip quality. The causes of stem-end chip defects are poorly understood. RESULTS: Chipping potatoes were grown under controlled environmental conditions to test the hypothesis that stem-end chip defect is caused by transient heat stress during the growing season. Heat stress periods with 35 °C days and 29 °C nights were imposed approximately 3 months after planting and lasted for 3, 7 or 14 days. At harvest and after 1, 2 and 3 months of storage at 13 °C, potato tubers were evaluated for glucose, fructose, sucrose and dry matter contents at the basal and apical ends. Chips were fried and rated for defects at the same sampling times. Differences in responses to heat stress were observed among four varieties of chipping potatoes. Heat stress periods of 7 and 14 days increased reducing sugar content in the tuber basal and apical ends, decreased dry matter content, and increased the severity of stem-end chip defects. CONCLUSION: Transient heat stress during the growing season decreased post-harvest chipping potato quality. Tuber reducing sugars and stem-end chip defects increased while dry matter content decreased. Planting varieties with tolerance to transient heat stress may be an effective way to mitigate these detrimental effects on chipping potato quality. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

Suppression of the vacuolar invertase gene delays senescent sweetening in chipping potatoes.

BACKGROUND: Potato chip processors require potato tubers that meet quality specifications for fried chip color, and color depends largely upon tuber sugar contents. At later times in storage, potatoes accumulate sucrose, glucose, and fructose. This developmental process, senescent sweetening, manifests as a blush of color near the center of the fried chip, becomes more severe with time, and limits the storage period. Vacuolar invertase (VInv) converts sucrose to glucose and fructose and is hypothesized to play a role in senescent sweetening. To test this hypothesis, senescent sweetening was quantified in multiple lines of potato with reduced VInv expression. RESULTS: Chip darkening from senescent sweetening was delayed by about 4 weeks for tubers with reduced VInv expression. A strong positive correlation between frequency of dark chips and tuber hexose content was observed. Tubers with reduced VInv expression had lower hexose to sucrose ratios than controls. CONCLUSION: VInv activity contributes to reducing sugar accumulation during senescent sweetening. Sucrose breakdown during frying may contribute to chip darkening. Suppressing VInv expression increases the storage period of the chipping potato crop, which is an important consideration, as potatoes with reduced VInv expression are entering commercial production in the USA. © 2017 Society of Chemical Industry.

Potential of carboxymethyl cellulose coating and low dose gamma irradiation to maintain storage quality, inhibit fungal growth and extend shelf-life of cherry fruit.

Carboxymethyl cellulose (CMC) coatings alone and in combination with gamma irradiation was tested for maintaining the storage quality, inhibiting fungal incidence and extending shelf-life of cherry fruit. Two commercial cherry varieties viz. Misri and Double after harvest at commercial maturity were coated with CMC at levels 0.5-1.0 % w/v and gamma irradiated at 1.2 kGy. The treated fruit including control was stored under ambient (temperature 25 ± 2 °C, RH 70 %) and refrigerated (temperature 3 ± 1 °C, RH 80 %) conditions for evaluation of various physico-chemical parameters. Fruits were evaluated after every 3 and 7 days under ambient and refrigerated conditions. CMC coating alone at levels 0.5 and 0.75 % w/v was not found effective with respect to mold growth inhibition under either of the two conditions. Individual treatment of CMC coating at 1.0 % w/v and 1.2 kGy irradiation proved helpful in delaying the onset of mold growth up to 5 and 8 days of ambient storage. During post-refrigerated storage at 25 ± 2 °C, RH 70 %, irradiation alone at 1.2 kGy gave further 4 days extension in shelf-life of cherry varieties following 28 days of refrigeration. All combinatory treatments of CMC coating and irradiation proved beneficial in maintaining the storage quality as well as delaying the decaying of cherry fruit during post-refrigerated storage at 25 ± 2 °C, RH 70 % but, combination of CMC at 1.0 % w/v and 1.2 kGy irradiation was found significantly (p ≤ 0.05) superior to all other treatments in maintaining the storage quality and delaying the decaying of cherry fruit. The above combinatory treatment besides maintaining storage quality resulted in extension of 6 days in shelf life of cherry varieties during post-refrigerated storage at 25 ± 2 °C, RH 80 % following 28 days of refrigeration. Above Combination treatment gave a maximum of 2.3 and 1.5 log reduction in yeast and mold count of cherry fruits after 9 and 28 days of ambient and refrigerated storage, thereby ensuring consumer safety.

Effect of packaging methods and crude aloe vera gel (Aloe vera barbadensis miller) on the storage quality of enrobed goat meat bites.

The storage stability of enrobed goat meat bites (EGMB) incorporated with 3 % crude aloe vera (AV) gel was evaluated under aerobic (T-1; unenrobed control product, T-2; enrobed AV treated product) and modified atmospheric packaging (MAP, 50:50, CO2 and N2) (T-3; unenrobed control product, T-4; enrobed AV treated product) at 4 ± 1 °C for 42 days on the basis of physico-chemical, microbiological and sensory attributes. The pH value was higher, whereas water activity (aW) was lower in enrobed and MAP product. Thiobarbituric acid reacting substances (TBARS) and free fatty acid (FFA) values were significantly (P < 0.05) lower in MAP packaged (T-3) and AV treated products (T-2 and T-4) products than aerobic packaged (T-1), however it followed an increasing trend in all the products throughout storage. Instrumental colour and textural profile attributes were better maintained in MAP products than others. The sensory panellists graded T-4 'good to very good' even on Day 42, whereas T-1 was acceptable only up to 28 days. Standard Plate Count (SPC) was significantly (P < 0.05) lower in MAP products than aerobic packaged products. Results concluded that EGMB treated with AV gel can be successfully stored more than 42 days under MAP conditions without affecting its physico-chemical, textural, microbiological and sensory attributes.

Synergistic effect of ultraviolet radiation and high hydrostatic pressure on texture, color, and oxidative stability of refrigerated tilapia fillets.

BACKGROUND: The isolated application of high hydrostatic pressure (HHP) and ultraviolet-C (UV-C) radiation may induce physicochemical changes, thus jeopardizing fish quality attributes during refrigerated storage, which could be minimized by the use of synergistic treatments. Therefore, this study investigated the combined effect of UV-C at 0.103 ± 0.002 J cm−2 and HHP at 220 MPa for 10 min on quality parameters of tilapia fillets stored at 4 °C for 15 days. RESULTS: HHP and UV-C+HHP showed higher myoglobin concentration, higher metmyoglobin-reducing activity, and lower a* than control and the UV-C treatment (P < 0.05), reaching 2.49, 2.58, 1.62, 1.54 mg myoglobin g−1 , 13.30, 13.81, 2.29, 2.29%, and 2.32, 2.58, 4.29, 3.98 respectively on the last day of storage. UV-C, HHP, and UV-C+HHP increased water-holding capacity and decreased the pH levels, hardness, and chewiness (P < 0.05). HHP retarded lipid oxidation and UV-C increased protein oxidation compared with control (P < 0.05), achieving 0.81 and 2.80 mg malondialdehyde per kilogram of fish tissue, and 5.50 and 4.15 nmol carbonyl per milligram of protein respectively on 15th day of the storage. CONCLUSION: Both technologies (alone or together) enhanced texture parameters and water-holding capacity. UV-C did not induce color changes and lipid oxidation, whereas HHP showed high potential to prevent meat discoloration, lipid oxidation, and protein oxidation. In addition, this combination of methods could be an alternative to prevent protein oxidation induced by UV-C.

Study on the Effect of Sorghum Flour Particle Size on the Storage Quality of Leavened Pancakes.

Pancakes prepared with sorghum flour possess a high nutritional value, yet their quality is unstable and prone to degradation during storage. This instability can be attributed to the particle size of coarse cereal powder, which significantly influences the quality of flour products during storage. In this study, changes in the quality of these pancakes, prepared with varying particle sizes of sorghum flour, were meticulously analyzed during cold storage using advanced instruments such as a texture analyzer, nuclear magnetic resonance spectrometer, differential scanning calorimeter, X-ray diffractometer, and Fourier transform infrared spectrometer. Findings revealed that the hardness of leavened pancakes significantly increased over time. After a refrigeration period of 7 days, the hardness of wheat flour leavened pancakes increased by 56.60%. However, with a decrease in the particle size of sorghum flour, the increase in hardness diminished, thereby delaying the aging process of the pancakes. As the storage duration was extended, moisture migration within the pancakes occurred, and the sorghum flour pancakes with a smaller particle size exhibited a reduced moisture change rate, indicating an enhanced water holding capacity. In comparison to their wheat flour counterparts, sorghum flour leavened pancakes exhibited a substantial reduction in retrogradation enthalpy and crystallinity. The inclusion of sorghum flour effectively inhibited amylopectin recrystallization, thus slowing down the aging process of the pancakes. This inhibitory effect was more evident with decreasing sorghum flour particle sizes. Fourier transform infrared data indicated no significant alterations in absorption peaks across various wavelengths during cold storage. Although starch short-range orderliness increased with storage time, the use of sorghum flour with smaller particles reduced the degree of short-range orderliness in starch molecules throughout the cold storage period. Sorghum flour with a smaller particle size can inhibit water migration and amylopectin recrystallization, which subsequently delays pancake aging and enhances its quality stability during storage.

Improving the storage quality of Harbin red sausages by quaternized chitosan/sodium alginate coating curcumin nano-emulsion.

In this study, the effect of sodium alginate and quaternized chitosan bis-polysaccharide-based shell transport curcumin nano-emulsions (Cur@QCS/SA) on the microbiological, physicochemical properties, quality characteristics of Harbin red sausage during storage is investigated. According to the microbiological results, the shelf life of Harbin red sausage is extended from 3 d to 6 d by adding 0.15% Cur@QCS/SA, and Bacillus is the most predominant bacterial before 6 d. Additionally, the physicochemical properties change significantly, the pH, weight loss (WL), water holding capacity (WHC), water activity (aw), L*, and a* of red sausage decrease gradually with the extension of storage time, as well as b*, lipid oxidation, proteolysis increase significantly (P < 0.05). Secondly, it is found that 0.15% treatment group can better maintain the quality characteristics of Harbin red sausage according to texture profile analysis (TPA), electronic nose (E-nose), and electronic tongue (E-tongue) (P < 0.05). This study provides a new way for nano-emulsions in food applications and a new option for the preservation of Harbin red sausage as well as other low-temperature meat products.

Mechanical Damage Caused by Compression and Its Effects on Storage Quality of Mandarin.

Mandarin is vulnerable to a range of external loads during processing and shipping, which can cause interior mechanical damage that can happen right away or over time and cause serious rotting when kept in storage. In this study, mandarin was treated to a certain quantity of compression load that did not result in a noticeable rupture of the peel. The interior pulp structure of mandarin was examined for damage prior to peel damage using CT scanning and image reconstruction. An image segmentation method based on mask processing was then used to calculate the pulp damage rate. We examined the variations in physiological activities and internal components between the test group that underwent compression load and the control group that did not undergo this type of stress during storage. The aim was to investigate the factors that contributed to the faster decay of mandarin following mechanical damage. Regression analysis was also used to establish a quantifiable relationship between the amount of compression deformation and the rates of damage and decay of mandarin during storage. The findings demonstrated that mandarin pulp exhibited visible mechanical damage when compression deformation exceeded 8 mm. This led to the disruption of physiological processes like respiration and polysaccharide breakdown, which in turn decreased the hardness of the fruit and sped up its rotting. This study identifies the critical range of compression deformation that leads to the beginning of pulp damage in mandarins. Additionally, it clarifies the quality deterioration mechanism of mandarins that have been subjected to compression damage during the storage period. Therefore, in practical production, various methods of picking, sorting, and collecting mandarins can be optimized to control the amount of compression deformation within a suitable range. This will reduce the probability of pulp damage. According to the study's conclusions, storage conditions can be optimized to regulate the physiological activities of mandarins in a targeted manner. This can minimize the probability of fruit decay and reduce economic losses.

Comparison of Fruit Texture and Storage Quality of Four Apple Varieties.

Fruit texture and storage properties of various apple varieties exhibit significant variation. The rate of fruit softening post-harvest plays a crucial role in determining fruit quality and shelf life. This research utilized four apple varieties as test subjects to investigate the internal factors influencing fruit texture changes among different varieties. By monitoring changes in relevant physiological indicators during the post-harvest texture softening process, the study examined fruit quality, cell wall material content, hydrolase activity, and gene transcription levels during storage of 'Orin', 'RX', 'RXH', and 'Envy' apples. Initial fruit softening was primarily linked to heightened post-harvest fruit respiration intensity, ethylene production, and rapid amylase activity. Subsequent softening was associated with increased activity of water-soluble pectin (WSP), cellulose (CEL), and other hydrolases. With the extension of the storage period, the fruit cells of the four varieties became more loosely arranged, resulting in larger intercellular gaps. Variations in WSP and cellulose content, CEL activity, and relative expression of Mdß-gal were observed among the different apple varieties, potentially accounting for the disparities in fruit texture.