Chitosan and mint mixture: A new preservative for meat and meat products

Effects of sodium alginate coating containing Mentha spicata essential oil and cellulose nanoparticles on extending the shelf life of raw silver carp (Hypophthalmichthys molitrix) fillets

The aim of the present study was to evaluate the effects of sodium alginate (SA) coatings containing Mentha spicata essential oil (MSO; 0.5 and 1%) and cellulose nanoparticles (CN; 0.25 and 0.5%) on chemical (total volatile base nitrogen content and peroxide value), microbial (total viable count, psychrotrophic count, Pseudomonas spp., and Enterobacteriaceae), and sensory (odor, color, and overall acceptability) properties of raw silver carp fillets during 14 days of refrigerated storage. The MSO was mostly comprised of carvone (78.76%) and limonene (11.50%). SA + MSO 1% + CN 0.5% was most effective in extending the shelf life of silver carp fillets, followed by SA + MSO 1% + CN 0.25%, SA + MSO 1%, SA + MSO 0.5% + CN 0.5%, SA + MSO 0.5% + CN 0.25%, SA + MSO 0.5%, SA + CN 0.5%, SA +CN  0.25%, and SA. Incorporation of MSO 0.5% didn't have any adverse effect on odor, color, and overall acceptability of treated samples.

Modified Starch-Chitosan Edible Films: Physicochemical and Mechanical Characterization

Starch and chitosan are widely used for preparation of edible films that are of great interest in food preservation. This work was aimed to analyze the relationship between structural and physical properties of edible films based on a mixture of chitosan and modified starches. In addition, films were tested for antimicrobial activity against Listeria innocua. Films were prepared by the casting method using chitosan (CT), waxy (WS), oxidized (OS) and acetylated (AS) corn starches and their mixtures. The CT-starches films showed improved barrier and mechanical properties as compared with those made from individual components, CT-OS film presented the lowest thickness (74 ± 7 µm), water content (11.53% ± 0.85%, w/w), solubility (26.77% ± 1.40%, w/v) and water vapor permeability ((1.18 ± 0.48) × 10−9 g·s−1·m−1·Pa−1). This film showed low hardness (2.30 ± 0.19 MPa), low surface roughness (Rq = 3.20 ± 0.41 nm) and was the most elastic (Young’s modulus = 0.11 ± 0.06 GPa). In addition, films made from CT-starches mixtures reduced CT antimicrobial activity against L. innocua, depending on the type of modified starch. This was attributed to interactions between acetyl groups of AS with the carbonyl and amino groups of CT, leaving CT with less positive charge. Interaction of the pyranose ring of OS with CT led to increased OH groups that upon interaction with amino groups, decreased the positive charge of CT, and this effect is responsible for the reduced antimicrobial activity. It was found that the type of starch modification influenced interactions with chitosan, leading to different films properties.

Pemanfaatan Kitosan Termodifikasi Asam Askorbat sebagai Bahan Antimikroba pada Daging Ayam Karkas Broiler

Daging ayam yang umumnya berupa daging ayam karkas broiler merupakan salah satu bahan pangan yang banyak dikonsumsi dan mudah busuk sehingga diperlukan bahan pengawet alternatif alami dan tidak berbahaya seperti kitosan. Penelitian ini bertujuan untuk memperoleh kitosan termodifikasi asam askorbat yang digunakan sebagai pengawet pada daging ayam karkas broiler pada suhu dingin. Dan untuk memperoleh data kemampuan pengawetan antara kitosan dan kitosan termodifikasi asam askorbat serta menentukan konsentrasi efektif asam askorbat yang ditambahkan dalam modifikasi kitosan sebagai pengawet daging ayam. Metode yang digunakan untuk dalam pengawetan adalah metode coating. Gugus fungsi kitosan-asam askorbat dianalisis menggunakan FTIR dan untuk menguji kemampuan kitosan termodifikasi asam askorbat sebagai pengawet daging ayam dilakukan analisis Angka Lempeng Total (ALT). Hasil penelitian menunjukkan bahwa kemampuan kitosan termodifikasi asam askorbat lebih baik dibandingkan kitosan tanpa modifikasi. Konsentrasi asam askorbat optimum adalah pada konsentrasi 40 mmol/L dan mampu mengawetkan daging ayam hingga 4 minggu.

Preservation Mechanism of Chitosan-Based Coating with Cinnamon Oil for Fruits Storage Based on Sensor Data

The chitosan-based coating with antimicrobial agent has been developed recently to control the decay of fruits. However, its fresh keeping and antimicrobial mechanism is still not very clear. The preservation mechanism of chitosan coating with cinnamon oil for fruits storage is investigated in this paper. Results in the atomic force microscopy sensor images show that many micropores exist in the chitosan coating film. The roughness of coating film is affected by the concentration of chitosan. The antifungal activity of cinnamon oil should be mainly due to its main consistent trans-cinnamaldehyde, which is proportional to the trans-cinnamaldehyde concentration and improves with increasing the attachment time of oil. The exosmosis ratios of Penicillium citrinum and Aspergillus flavus could be enhanced by increasing the concentration of cinnamon oil. Morphological observation indicates that, compared to the normal cell, the wizened mycelium of A. flavus is observed around the inhibition zone, and the growth of spores is also inhibited. Moreover, the analysis of gas sensors indicate that the chitosan-oil coating could decrease the level of O₂ and increase the level of CO₂ in the package of cherry fruits, which also control the fruit decay. These results indicate that its preservation mechanism might be partly due to the micropores structure of coating film as a barrier for gas and a carrier for oil, and partly due to the activity of cinnamon oil on the cell disruption.

Physicochemical and Antibacterial Properties of Chitosan Extracted from Waste Shrimp Shells

This research aims to study the production of chitosan from shrimp shell (Litopenaeus vannamei) of waste origin using two chemical methodologies involving demineralization, deproteinization, and the degree of deacetylation. The evaluation of the quality of chitosan from waste shrimp shells includes parameters for the yield, physical chemistry characteristics by infrared spectroscopy (FT-IR), the degree of deacetylation, and antibacterial activity. The results showed (by Method 1) extraction yields for chitin of 33% and for chitosan of 49% and a 76% degree of deacetylation. Chitosan obtained by Method 2 was more efficient: chitin (36%) and chitosan (63%), with a high degree of deacetylation (81.7%). The antibacterial activity was tested against Gram-negative bacteria (Stenotrophomonas maltophilia and Enterobacter cloacae) and Gram-positive Bacillus subtilis and the Minimum Inhibitory Concentrations (MIC) and the Minimum Bactericidal Concentration (MBC) were determined. Method 2 showed that extracted chitosan has good antimicrobial potential against Gram-positive and Gram-negative bacteria and that the process is viable.

Effects of glycinin basic polypeptide on sensory and physicochemical properties of chilled pork

Effects of glycinin basic polypeptide (GBP) on sensory and physicochemical properties of pork during chilled storage were investigated. Pork treated with GBP was analyzed periodically for sensory properties, pH, total volatile base nitrogen (TVB-N), α-thiobarbituric acid (TBA), and total viable count (TVC) values. Compared with controls, TBA values of pork treated with GBP did not change. TVB-N, pH, and TVC values of pork showed reductions with increasing concentrations of GBP during 8 days of storage. However, there were increases in sensory scores. TVC values of treated pork showed a positive linear relationship with both pH and TVB-N values. GBP at 0.16 and 0.20% efficiently inhibited bacterial growth, and enhanced chilled pork sensory scores. Therefore, GBP has potential as a pork biological preservative for extension of shelf life during chilled storage.

Synthesis and screening of N-acyl thiolated chitosans for antibacterial applications

Low-molecular weight chitosan-thioglycolic acid has shown significant antibacterial properties against different microorganisms. In order to explore the potential and structure-activity relationships of newly synthesized alkyl thiomers, chitosan has been functionalized with a series of thio-acids with increasing alkyl chain length. All thiomers were characterized with special emphasis on the determination of their degree of deacetylation and substitution, as well as on their molecular weight and amount of thiol groups. The pre-screened chitosan-thiomers were further investigated with plate counting on Pseudomonas aeruginosa, Streptococcus sobrinus and Streptococcus mutans. Furthermore, LIVE/DEAD assays supported the efficiency of chitosan-thiomers against the above microorganisms. All fully characterized chitosan-thiomers showed comparable or enhanced antimicrobial activity compared to pristine chitosan. Our comprehensive approach paves the way to detailed explorations of much sought-after structure activity relationships in the complex chitosan parameter room, starting from correlations between alkyl chain length and antimicrobial activity.

A chitosan-based coating with or without clove oil extends the shelf life of cooked pork sausages in refrigerated storage

Chitosan coatings, with and without clove oil, were investigated for effects on quality and shelf life of cooked pork sausages stored at a refrigerated temperature (4±2°C). The various treatments of cooked pork sausages were: untreated (control), coating with 2% chitosan (CS), and coating with a mixture having 2% chitosan and 1.5% clove oil (CS+CO). Various microbiological, physical, chemical and sensory properties were monitored over 25 days of storage. The total viable count, the psychrotrophic bacteria count, the L* value, peroxide value and the thiobarbituric acid reactive substances increased, while the a* value, the b* value, the pH and the sensory scores decreased with storage time, across all treatments. However, these changes were slowest with the CS+CO treatment. Based on sensory evaluation and microbiological quality, the shelf lives were 14 days for control, 20 days for CS, and 20 days for CS+CO treated samples, under refrigerated storage.

Effect of chitosan coating with cinnamon oil on the quality and physiological attributes of China jujube fruits

Effects of chitosan coating with cinnamon oil on the physiological attributes and preservation quality of China jujube fruits during storage at 4°C for 60 days were investigated. Results indicated that weight loss and decay of jujube fruits were significantly reduced by chitosan-oil coating during the period of 60-day storage, which also exhibited a quite beneficial effect on maintaining the sensory quality for jujube fruits. Meanwhile, the contents of vitamin C and titratable acid decreased to 3.08 mg·g(-1) and 0.342% for the fruits treated by chitosan-oil coating (1.0% + 0.10%), respectively. Polyphenol oxidase, superoxide dismutase, and peroxidase activities were 13.40 U·g(-1), 14.53 U·g(-1), and 63.6 U·g(-1) at the end of storage, respectively. The contents of total soluble phenolics and MDA were 34.51 mg·g(-1) and 19.43 μmol·g(-1) for the combined coating treated samples and control fruits, respectively. These results suggested that the chitosan-oil coating might be recognized as one efficiency technology on the preservation quality of jujube fruits during the storage time.

Efficacy of mint (Mentha arvensis) leaf and citrus (Citrus aurantium) peel extracts as natural preservatives for shelf life extension of chill stored Indian mackerel

Efficacy of mint (Mentha arvensis) leaf and citrus (Citrus aurantium) peel extracts in retarding the quality changes in Indian mackerel during chilled storage was investigated. Mint leaf extract showed higher quantity of phenolics and superior in-vitro antioxidant activities than citrus peel extract. Gutted mackerel were given a dip treatment in mint extract (0.5 %, w/v) and citrus extract (1 % w/v), packed in LDPE pouches and stored at 0-2 °C. The biochemical quality indices viz. total volatile base nitrogen (TVB-N), trimethylamine nitrogen (TMA-N), free fattyacids (FFA) were significantly (p < 0.05) lower in mint extract (ME) treated fishes compared to citrus extract (CE) treated and control fishes (C) without any treatment. Plant extract treatment significantly inhibited lipid oxidation in mackerel as indicated by peroxide value (PV) and thiobarbituric acid reactive substances (TBARS). Aerobic plate count (APC) was markedly higher in C group followed by CE group throughout the storage period. As per sensory evaluation, shelf life of Indian mackerel was determined to be 11-13 days for C group, 13-15 days for CE group and 16-17 days for ME group, during storage at 0-2 °C.

Effect of chitosan edible films added with Thymus moroderi and Thymus piperella essential oil on shelf-life of cooked cured ham

The aim of this work was to develop chitosan edible films added with essential oils obtained from two Thymus species, Thymus moroderi (TMEO) and Thymus piperella (TPEO) to determine their application for enhancing safety (antioxidant and antibacterial properties) and shelf-life of cooked cured ham (CCH) stored at 4 °C during 21 days. Addition of TMEO and TPEO into chitosan films decreased the aerobic mesophilic bacteria (AMB) and lactic acid bacteria (LAB) counts in coated cooked cured ham samples as compared with uncoated samples. Both AMB and LAB showed the lowest counts in CCH samples coated with chitosan films added with TPEO at 2 %. In regard to lipid oxidation, the CCH samples coated with chitosan films added with TMEO or TPEO had lower degrees of lipid oxidation than uncoated control samples. Chitosan films added with TPEO at 2 % showed the lowest values. The addition of TPEO or TMEO in chitosan films used as coated in CCH improved their shelf life.

Preparation of Clove Essential Oil Microencapsule and Study on its Performance

In this paper,the clove essential oil was combined with β-Cyclodextrin and chitosan using the method of envelope binding,thus clove essential oil microencapsule antistaling agent was prepared.To detect the exterior characterization of microcapsule using SEM;To analyze the antimicrobial properties of microencapsules using the inhibition zone method, and the slow release rate of microencapsule was detected in 0, 2,30 °C. The results showed that the microencapsule had irregular shapes and their surfaces were covered with many cracks;the inhibition zone diameter of Rhizopus sp. and Penicillium citrinum diameter were 1.2 cm and 1.6 cm partly; microencapsules showed a slow release state under the three temperature conditions,and it had the slowest release rate under 0 °C condition.

Effect of meadowsweet flower extract-pullulan coatings on rhizopus rot development and postharvest quality of cold-stored red peppers

The study involved an examination of the antifungal activity on red peppers of pullulan coating (P) and pullulan coating containing either water-ethanol (P + eEMF) or ethanol extract of meadowsweet flowers (P + eEMF). Pullulan was obtained from a culture of Aureobasidium pullulans B-1 mutant. Both non-inoculated peppers and those artificially inoculated with Rhizopus arrhizus were coated and incubated at 24 °C for 5 days. The intensity of the decay caused by Rhizopus arrhizus in the peppers with P and P + eEMF coatings was nearly 3-fold lower, and in the case of P + weEMF 5-fold lower, than that observed in the control peppers. Additionally, the P + weEMF coating decreased, almost two-fold the severity of pepper decay compared to other samples. The influence of coating of pepper postharvest quality was examined after 30 days of storage at 6 °C and 70%-75% RH. All coatings formed a thin and well-attached additional layer of an intensified gloss. During storage, color, total soluble solid content and weight loss of coated peppers were subject to lower changes in comparison with uncoated ones. The results indicate the possibility of the application of pullulan coatings containing MFEs as an alternative to the chemical fungicides used to combat pepper postharvest diseases.