Psychrotrophic Counts Research Articles

Films from Starch Inclusion Complexes with Bioactive Compounds as Food Packaging Material

Abstract Natural polymers are an alternative to plastics in food packaging applications due to their biodegradability, and starch is a promising candidate due to its abundance and low cost. Furthermore, amylose has the ability to form inclusion complexes with bioactive compounds, ensuring their stability; nevertheless, this property has not been exploited in food packaging applications. In the present study, films from starch inclusion complexes with bioactive compounds (carvacrol and ascorbic acid) were developed and tested as food packaging material. The formation of starch inclusion complexes resulted in films with enhanced tensile strength, without compromising their flexibility, water vapor permeability, and transparency. Fresh minced meat was packaged in films from starch inclusion complexes with bioactive compounds and refrigerated for 4 days. Films from starch inclusion complexes with ascorbic acid had the highest antioxidant activity, resulting in the most appealing color properties, while films from starch inclusion complexes with carvacrol had the highest antimicrobial activity, resulting in smaller increases in aerobic plate and psychrotrophic count. Consequently, the formation of starch inclusion complexes with bioactive compounds is a promising technology for the development of biodegradable, active food packaging materials.

Study on The Impact of Gelatin Coating Containing Lactobacillus acidophilus and Lactobacillus reuteri on Chicken Fillets Shelf Life

The purpose of this study is to assess how chicken fillet shelf life and sensory evaluation are affected by 1% Gelatin coating containing Lactobacillus acidophilus PTCC 1643 and Lactobacillus reuteri ATCC 1655. Probiotic-containing cultures were introduced straight to the coating solution in this investigation. Measures were taken of the chemical (pH, TVB-N, peroxide value), microbiological (Total viable count (TVC), psychrotrophic count (PTC), Enterobacteriaceae, and Pseudomonas spp.), and sensory properties. During the storage of the chicken fillet, which was kept at 4° C for intervals of 0, 3, 6, 9, and 12 days, the antimicrobial properties of the coating in the groups treated with gelatin, Lactobacillus acidophilus, and Lactobacillus reuteri were significantly (p<0.05) higher than those in the control groups, despite the fact that the results showed the highest chemical properties and sensory score across all parameters. However, gelatin + Lactobacillus reuteri and gelatin + Lactobacillus acidophilus did not differ significantly (p<0.05). Additionally, samples treated with gelatin and probiotics showed no changes in color or texture, but their odor and taste scores decreased. We draw the conclusion that gelatin is an appropriate matrix for probiotic incorporation and long-term fillet storage.

Evaluation of whey protein coating containing free and Pickering emulsion forms of Trachyspermum copticum L. essential oil on quality of refrigerated beef.

The purpose of the present research was to prepare a novel biodegradable coating of whey protein (whey) and essential oil of Trachyspermum copticum L. (forms of free (EO) and Pickering emulsion (NEO)) to improve the shelf life of beef. In this study, various microbiological, chemical, and sensory analyses were performed. The results showed that after 18 days, the highest and lowest microbiological counts were related to control samples and whey-NEO treatments, respectively. The total viable count (TVC) was 8.2 and 6.8 log CFU/g, the total psychrotrophic count (TPC) was 8.5 and 6.7 log CFU/g, and the lactic acid bacteria (LAB) count was 7.7 and 6.5 log CFU/g for control and whey-NEO treatments, respectively. Chemical analysis of whey-NEO treatment and control sample were 6.3 and 7.5 for pH, 9.8 and 13.9 meq/kg for PV (peroxide value), 5.45 and 8.85 mg/kg for TBARS (thiobarbituric acid reactive substances), and 25.1 and 39.4 mgN/100 g for TVB-N (total volatile basic nitrogen), respectively. The best result was associated with the whey-NEO treatment; consequently, coatings with whey and EO Pickering emulsion should be considered as a potential active coating in the meat industry.

Effect of Dry Aging of Pork on Microbiological Quality and Instrumental Characteristics

Meat aging is an important process that affects the quality of meat and is traditionally used mainly for beef. However, in recent years, there has been an increasing demand for pork products subjected to dry aging. The aim of this study was to compare selected parameters (microbiological quality, instrumental analyses of texture and color of meat, weight loss) of pork neck and loin with bone and skin together subjected to dry aging for 14 days. The microbiological profile (total viable psychrotrophic count, Enterobacteriaceae, psychrotrophic lactic acid bacteria, Pseudomonas spp.) on the surface of the meat with the skin and the lateral cutting surfaces without skin was compared on the first day after slaughter and after 14 days of dry aging. The results of this study demonstrated that dry aging did not significantly deteriorate the microbiological profile. Statistically significant weight losses were observed after 14 days of aging. The dry aging of pork had no significant effect on lightness (L*), redness (a*), and shear force. Significant differences were observed for yellowness (b*) and meat hardness (p < 0.05).

Malva neglecta seed polysaccharide mucilage coating enriched by the Lactobacillus brevis TD4 postbiotics: A promising strategy to promote the shelf life of fresh beef

The need for bioactive-incorporated biodegradable packaging products is growing due to the desire to achieve food goods that have a longer shelf life and enhanced safety. The current study set out to create an edible coating using Malva neglecta seed polysaccharide mucilage (MNSM) containing Lactobacillus brevis TD4-derived postbiotics (PLB), and assess how well the PLB-MNSM edible coating preserved beef slices over a 12-day period of refrigeration. PLB was rich in fatty acids, organic heteropolycyclic compounds, monoterpene and cyclohexanol derivative, prenol lipids, ester compounds, and alpha-CH2-containing aldehyde with significant antimicrobial and antioxidant activities. By adding it to the edible coating at 0, 5, 10, and 15 % v/v, it successfully prevented the proliferation of microbial agents (total viable count, psychrotrophic count, Staphylococcus aureus, Escherichia coli, total coliform bacteria count, and fungi) as well as the oxidation of lipids (thiobarbituric and peroxide values) in beef samples. The samples' pH value, hardness, and moisture content were all more successfully sustained when PLB preparation was applied to the coating solution (P < 0.05). The edible coating consisting of PLB effectively maintained the meat color (L*, a*, b*) and sensory properties. Additionally, the bioactive edible coating comprised of MNSM and PLB, specifically MNSM-15 % PLB, significantly prevented the quality deterioration of beef samples and prolonged the shelf-life of the meat to over 12 days. The outcomes indicated that the MNSM-PLB edible coating has the capacity to be utilized as an antibacterial and antioxidant-rich packing material, hence enhancing the shelf life of meat-based goods.

Evaluation of Lipid Damage, Microbial Spoilage and Sensory Acceptance of Chilled Pouting (Trisopterus luscus), an Underutilized Lean Fish Species

The present study focused on the use of pouting (Trisopterus luscus), an underutilized gadoid fish species, as a fresh product of potential commercial interest. Accordingly, non-degutted pouting specimens (145–195 g and 15–22 cm) were stored under chilling conditions (0 °C) for microbial, chemical and sensory analyses to evaluate their commercial quality and shelf life. A progressive quality loss (p &lt; 0.05) was detected for this lean species (5.58 g lipids·kg−1 muscle) as the storage time increased, as determined through microbial (aerobes, psychrotrophs and Enterobacteriaceae counts), lipid hydrolysis (free fatty acid value), lipid oxidation (conjugated diene and triene, thiobarbituric acid reactive substance, and fluorescence values) and sensory acceptance assessment. A detailed comparison to related lean fish species revealed that the pouting exhibited a fast quality breakdown under refrigeration conditions. Thus, after 9 d of chilled storage, the psychrotroph counts exceeded the acceptable limits (8.54 log CFU·g−1), and the fish specimens were found to be rejectable, with the sensory panel, external odor and eye appearance being the limiting factors. In contrast, the pouting specimens exhibited high quality after 3 d of storage, with the quality being still acceptable after 6 d. According to the current search for novel, underutilized species, pouting is proposed as a promising source.

In-package cold atmospheric plasma processing for shelf-life extension of gilthead seabream (Sparus aurata) fillets.

In-package cold atmospheric plasma (CAP) processing, which refers to the generation of CAP inside a sealed package, enables a local disinfecting reaction, allowing no post-process contamination and extending the shelf-life (SL) of perishable food products, such as fresh fish. In the present study, four in-package CAP treatments, differing in frequency and processing time, were applied on fresh gilthead seabream (Sparus aurata) fillets, prepacked in low-permeability pouches. Fish SL was evaluated during isothermal storage at 2°C, whereas untreated packaged fillets were used as control samples. The SL assessment of the fish fillets was based on microbial enumeration of total aerobic mesophilic count (TMC), total aerobic psychrotrophic count (TPC), Pseudomonas spp., Enterobacteriaceae, and lactic acid bacteria (LAB), pH measurement, determination of color and texture parameters, lipid oxidation, total volatile basic nitrogen (TVB-N) measurement, and sensory evaluation. All CAP treatments were effective against microbial inhibition in fish fillets, especially regarding TMC, TPC, and Pseudomonas spp., resulting in maximum reduction of 1.49, 1.24, and 1.43logCFU/g, respectively, compared to the control samples after 16 days of storage. However, minor effect was observed against Enterobacteriaceae and no effect against LAB. CAP processing did not affect the color and texture parameters of fish fillets, and TVB-N production was slightly reduced in CAP-treated samples; however, lipid oxidation was accelerated, especially at the more intense processing conditions, by a maximum of 75.5%. The results of the study indicated that in-package CAP processing could be effectively applied for inhibiting spoilage during refrigerated storage and extending SL of fresh fish fillets. PRACTICAL APPLICATION: In-package cold atmospheric plasma (CAP) processing was tested on gilthead seabream fillets, a highly perishable product with high commercial potential if its shelf-life can be extended through minimal processing. The food industry could benefit from in-package CAP technology as it is a cost effective nonthermal processing method while preventing post-processing contamination of the products. Although in-package CAP processing has not been extensively tested on fish, this study examined the quality and shelf-life of a highly perishable fish species, and the results could be further used as a reference for processing optimization of the CAP treatments.

Insights into the quality changes of edible sea urchin (Echinus esculentus) gonads during ice storage

The study aimed to assess the quality changes of E. esculentus gonads during 14-days of ice storage. Microbial quality and community composition succession were examined using both culture-dependent and independent methods. Additionally, the chemical profile, including spoilage metabolite production, proximate composition, fatty acids and amino acids distribution, was investigated. Colorimetric and texture parameters were also assessed. Microbial counts were relatively stable until day 4, followed by rapid growth, reaching 7.3 ± 0.1 log CFU/g on day 8 for psychrotrophic counts. Pseudomonas emerged as the primary specific spoilage organism, followed by Photobacterium and Psychrobacter. Concurrently, inosine, hypoxanthine and biogenic amines formation correlated with the rapid microbial proliferation. The fresh gonads' lipid consisted of 29.4 ± 1.0% SFA, 18.7 ± 1.0% MUFA and 46.5 ± 2.7% PUFA, with no significant changes up to day 8 of ice storage. The initial ratio of essential to non-essential amino acids was 62.3 ± 1.8% and declined during storage, while the concentration of free amino acids significantly increased after 4 days of ice storage. Notable shifts in the lightness and texture parameters coincided with the water content reduction. Overall, the results indicated satisfactory gonad quality for up to 4 days of ice storage, beyond which significant degradation and spoilage processes were initiated. This study could offer insights to enhance comprehension and prolong the quality stability of gonads.

Impact of Raw Milk Quality on Dairy Products &amp; Payment Systems

The trend of microbial quality of raw milk is affected by the seasonal variation in in milk production practices and ambient temperature with the season. A payment system, which includes testing for selected parameters, with subsequent rejection and/or penalties or bonuses, is considered functional to improving raw milk quality. In addition to the minimal legal requirements, milk may be graded (and paid) according to its “quality,” usually measured according to composition (fat, protein, lactose, other solids, free fatty acids), hygienic quality. Psychrotrophic microbes, particularly Pseudomonas spp., are found in the microbiota of chilled milk because they can grow at temperatures below their optimal growth temperature. Psychrotrophic counts ranging from 105 to 108 CFU/ml in refrigerated raw milk affect cheese quality, since the synthesized thermoresistant enzymes affect the nutritional value, sensory properties and texture. Therefore, stringent measures must be implemented throughout the dairy supply chain to ensure the microbial quality of raw milk is maintained at safe levels, thus safeguarding the integrity and safety of dairy products for consumers.

Oil-in-water emulsion loaded with optimized antioxidant blend improved the shelf-life of trout (Oncorhynchus mykiss) fillets: a study with simplex-centroid design.

This study aimed to obtain optimized mixture with three essential oils (EOs) for maximum antioxidant activity through the augmented simplex-centroid mixture design and evaluate the effect of this optimized blend on total aerobic psychrotrophic count (TAPC), lipid and protein oxidation, instrumental color parameters and texture profile in rainbow trout fillets at refrigerated storage for nine days. Considering the DPPH and FRAP assays, the ideal EO blend was 66% lemongrass and 34% oregano. During refrigerated storage, this blend at 2000ppm was equally effective as BHT (100ppm) (p > 0.05), mitigating the discoloration (a* and b*), lipid, and protein oxidation in 38.83%, 12.95%, 76.13%, and 35.13%, respectively, besides shows greater effectiveness for preserving texture changes (p < 0.05) and extending the shelf life in 13h. The lemongrass + oregano EO blend reveals a promising natural alternative to enhance the quality of rainbow trout fillets under refrigerated storage. Furthermore, the multiresponse optimization showed to be a strong ally in enabling the use of these EOs by food industries.

Red Propolis Prevents Lipid Oxidation and Reduces Microbial Growth in Fish Nuggets with Green Banana Flour

ABSTRACT Green banana flour (GBF) and hydroalcoholic extract of red propolis (HERP) imporve the nutricional quality and preservation of fish nuggets. The nuggets were formulated using 13% of GBF and different concentrations (0%, 0.4%, 0.6%, and 0.8%) of the HERP, while the control was without the addition of GBF and HERP. The addition of the HERP influenced (p < .05) the acceptance of the sensory attributes, with an acceptability index > 70%. The nuggets containing 0.4% of HERP presented ash, lipid, resistant starch, and polyphenol contents superior (p < .05) to the commercial brand fish nugget sample. After 15 days stored at 4°C, the nuggets treated with the HERP presented lower lipid oxidation and psychrotrophic counts, when compared to samples added with sodium erythorbate. The use of GBF improved the nutritional quality of the fish nuggets and EHPV reduced the lipid oxidation of the samples.

Thymbra capitata L. hydrolate as a washing solution for controlling Listeria monocytogenes and spoilage microorganisms on rocket salad

Ready-to-eat (RTE) vegetables, including fresh-cut ones, are exposed to the risk of the foodborne pathogen Listeria monocytogenes. Nowadays, fresh-cut products are widely consumed because of their convenience. Nevertheless, effective washing treatments are required for their preparation, to maintain freshness and microbiological safety. Currently, natural substances are increasingly demanded as alternatives to traditional synthetic washing agents. Therefore, this study investigates the application of Thymbra capitata hydrolate as washing solution for rocket salad (Eruca sativa) stored at 4 °C for 48 h, to evaluate a potential application both during the production process of fresh-cut vegetables, and also at the domestic level. The hydrolate applied at a concentration of 500 μL/mL for 5 min allowed to reduce L. monocytogenes load of about 1 log CFU/g at each time of analysis, and to determine a significant reduction of microbial groups normally found on rocket salad, particularly total mesophilic and psychrotrophic counts. The treatment showed no negative effects on pH, aw, and colour of the rocket salad. At a sensory level, the differences among control and treated samples were minimally perceived only on the first day of analysis but disappeared over time. Therefore, this alternative washing treatment revealed to counteract L. monocytogenes growth and to help maintaining the quality of rocket salad. Hence, it could be optimized for a concrete application, also considering the enhancement of the antilisterial activity, the sustainability and low cost of the hydrolate, which represents a by-product from the production of essential oils.

Quality survey of frozen chicken meat consumed at government hospitals throughout different seasons in Assiut city, Egypt

This study was conducted to evaluate the quality of frozen chicken meat received at government hospitals in Assiut city, Egypt, during hot and cold seasons. A total of 308 chicken meat samples were collected randomly and subjected to sensory, chemical, physical and microbiological testing. The findings showed that frozen chicken meat samples examined during the cold season had a better sensory evaluation than those examined during the hot season. The mean values of the physical quality tests, which included pH, drip loss, and water-holding capacity (WHC), were 6.12±0.017, 4.13±2.8, and 63.60±0.55 in the hot season and 5.9±0.013, 3.32±3.09, and 81.28±0.48 in the cold season, respectively. The total bacterial count, psychrotrophic count, total yeast and mould counts were 6.9×105±8.7×104, 1.1×106±1.0×105, 3.9×104±3.8×103, and 7.4×104±2.7×103 CFU/g in the hot season and 4.4×104±2.2×103, 1.9×105±1.6×104, 1.4×104±2.0×103, and 3.8×104±3.1×103 CFU/g in the cold season, respectively. These findings indicate that temperature has a significant impact on meat qua­lity; the frozen chicken meat samples examined in the cold season were in better condition than those examined in the hot season. It is necessary to maintain sanitary hygienic conditions during handling, packaging, storage and distribution particularly in the hot season.

Optimizing UVC-LED application to improve the shelf life of vacuum-packed refrigerated stored Nile tilapia (Oreochromis niloticus) fillets.

Although ultraviolet-C light-emitting diode (UVC-LED) has proven antimicrobial effectiveness doses needed to reach it cause adverse effects on the physicochemical quality of fish, and thus, optimization studies are crucial to boost its industrial application. This study aimed to identify optimal UVC-LED conditions for maximum shelf life extension with the least possible quality changes of refrigerated stored tilapia fillets from a central composite rotatable design (CCRD). UVC-LED powers (1, 1.38, and 1.58mW/cm2 ) and times (500, 1800, and 2700s) were set on the CCRD, which generated 11 treatments, including three replicate experiments. Treatments were analyzed for total aerobic psychrotrophic count, lipid oxidation, instrumental color, and texture parameters on days 0, 2, 4, 7, 11, and 14. The UVC-LED affected shelf life and physicochemical parameters in a nonlinear fashion. UVC-LED-treated fish had increased shelf life by 2.80-4.76 days and increase or decrease in lipid oxidation (0.025-0.276mg of malondialdehyde [MDA]/kg), total color change (∆E=3.47-9.06), and hardness (1.31-8.51N) over the refrigerated storage depending on specific UVC-LED conditions applied. The optimal UVC-LED condition was 0.97mW/cm2 with 2503.6s (2428.50mJ/cm2 ), which increased the fillet's shelf life by 2.5-fold (2 days) while maintaining quality closer to the original throughout refrigerated storage, resulting in ∆E<5, an increase of only 0.05mg of MDA/kg, and preservation of the decrease in hardness by 3.38N compared to its control counterparts. Therefore, it represents an eco-friendly technology that can easily scaled industrially to enhance the sustainable fish production chain. PRACTICAL APPLICATION: The high fish perishability is a global concern due to food safety risks and waste generation impacting the environment adversely, especially nowadays, where fish production and consumption have increased, and there are more evident efforts to sustainable production. UVC-LED is an eco-friendly technology with proven antimicrobial effectiveness but doses needed to reach this effect enhance oxidative degradation. Despite that, optimization studies concerning the maximum shelf life extension while retaining the physicochemical quality of refrigerated stored fish are a gap in the literature and a barrier to its industrial application. Our findings are helpful in sustainably enhancing the fish production chain.

Antimicrobial and antioxidant effects of an edible coating of Lepidium sativum seed mucilage and Satureja hortensis L. essential oil in Uncooked lamb meat

The current research aimed to fabricate an active edible coating, Lepidium sativum seeds mucilage (LSSM) loaded with Satureja hortensis essential oil (SHEO) (0, 0.5, 1, and 1.5 % (w/w)) for further extension of the shelf life of refrigerated lamb meat during storage for 18 days at (4 °C). The control and the coated lamb meat samples were continually analyzed for microbiological (total count, psychrotrophic count, yeast and mold), chemical (pH, moisture content, PV, and TBA), and sensory characteristics. Consistent with the microbiological analysis, the LSSM incorporated with 1, and 1.5% SHEO caused a significant shelf-life extension of the lamb meat by 15 and 18 days, respectively. These results suggested that (LSSM+1.5%S) sufficiently hindered the overall bacterial growth in the lamb meat sample since the shelf life in this treatment was 12 days more in comparison to the control. Hence, LSSM containing SHEO is very useful as an active packaging in order to preserve the quality and to prolong the lamb meat shelf life at 4 °C.

Improving the microbial quality and sensory properties of pasteurized sweet cream butter during refrigerated storage using chia seed ethanolic extract.

Butter is a perishable food, and its microbial deterioration occurs in refrigeration conditions, leading to a reduction in shelf life and a loss of sensory properties. This study aimed to investigate the effect of chia seed extract (CSE) on the microbial and sensory properties of pasteurized sweet cream butter at 2°C. Ethanolic extract of chia seeds was prepared and added to the butter samples in concentrations of 0.05%, 0.1%, 0.25%, and 0.5% (v/w), and its effects on microbiological and sensory quality were evaluated at 15-day intervals during 60-day refrigerated storage. The results indicated that the addition of 0.25% and 0.5% CSE to butter treatments decreased total viable counts by 0.25-0.6 log CFU/g, total psychrotrophic counts by 1-1.5 log CFU/g, and coliform counts by 3-4 log CFU/g compared to the control sample on days 45 and 60 of storage. Moreover, concentrations of 0.1%-0.5% CSE reduced mold and yeast counts by 1.5-2.6 log CFU/g on days 30-60 of storage compared to the control sample. Escherichia coli and Staphylococcus aureus were not detected in any samples during storage. CSE had a significant effect on the sensory properties (except for aroma) of the butter samples during the 60-day storage. The best color, flavor, and overall acceptance scores were assigned to the treatments containing 0.1%-0.5% CSE compared to the control sample. It could be concluded that adding 0.1% and 0.25% CSE to refrigerated and pasteurized butter can retard microbial spoilage and improve its sensory properties at the same time.

Evaluation of the physicochemical and microbial properties of lamb meat coated with Shirazi balangu seed mucilage-based edible coating containing cell-free supernatant of Levilactobacillus brevis G145

This study was aimed to design a novel edible coating based on Shirazi balangu seed mucilage (SBM) containing cell-free supernatant (CFS) of Levilactobacillus brevis G145 to improve the quality and shelf-life of lamb meat slices during cold storage. The CFS (1 and 2 %) was added to the SBM, and the obtained edible coating was used to coat the meat slices. The samples were stored at 4 °C for 1, 4, 7, and 10 days. In comparison to the control sample, the meat slices coated with SBM+2 %CFS had manifestly lower total viable count (6.62 vs. 13.10 log CFU/g), psychrotrophic count (3.47 vs. 8.80 log CFU/g), Escherichia coli count (0.80 vs. 1.54 log CFU/g), Staphylococcus aureus count (0.81 vs. 1.57 log CFU/g), fungi count (0.68 vs. 2.38 log CFU/g), pH (5.70 vs. 6.51), and peroxide value (4.89 vs. 10.80 meq O2/kg), and higher moisture content (70 vs. 60 %), hardness (67.80 vs. 57.60 N), and sensory properties by the end of storage period. The results of this study revealed that the SBM+CFS- based edible coating increased the shelf-life of lamb meat efficiently.

Extension of shelf life of Nile tilapia (Oreochromis niloticus) fillets using seaweed extracts during refrigerated storage.

The effects of seaweed (Padina tetrastromatica, Sargassum natans, and Sargassum fluitans) ethanolic extracts on the quality and shelf life extension of Nile tilapia (Oreochromis niloticus) fillets were investigated during refrigerated storage for 20 days. Each of the seaweed ethanolic extracts solution (2%, w/v) was used for dipping the fish fillets for 10 min at 4°C. The control and seaweed extract-treated fillets were stored at 4 ± 1°C in air-tight polyethylene bags, and chemical, bacteriological, and sensory evaluation were performed at every 4 days' intervals. During the storage period, P. tetrastromatica extract significantly (p < .05) reduced the increment of pH, peroxide value, thiobarbituric acid reactive substances, and total volatile basic nitrogen values in Nile tilapia fillets compared to other seaweed extracts-treated and untreated fillets. The maximal total viable count of control, P. tetrastromatica, S. natans, and S. fluitans extracts-treated fillets was 6.53, 7.11, 6.75, and 7.10 log CFU/g at the 8th, 20th, 12th, and 16th days of storage, respectively. The total psychrotrophic count of control and seaweed extracts-treated fillets was also significantly increased (p < .05) throughout the storage period. The P. tetrastromatica extracts-treated fillets showed better sensory characteristics than other seaweed extracts-treated and control fillets. Results of this study suggest that ethanolic extracts (2%, w/v) of P. tetrastromatica extend the shelf life for 12 days longer than the control fillets in refrigerated conditions.

Physico-chemical, sensory, and microbiological quality of raw chicken meat: an exploratory study in the Hisar city of Haryana, India.

A survey was conducted in Hisar, located in Haryana, India, to assess the quality of raw chicken meat. To ensure comprehensive coverage, healthy broiler chickens were obtained from various meat retail outlets in Hisar city, encompassing the majority of such establishments. Additionally, a sample of control chickens was obtained from the Livestock Farm, College of Veterinary Sciences, Lala Lajpat Rai University of Veterinary and Animal Sciences (LUVAS), Hisar, Haryana, India. The raw chicken meat was grouped into two categories, breast cut and thigh cut. The breast muscles, which include pectoralis major and pectoralis minor, and the thigh muscles, which include the abductor muscles, were chosen as the samples for proximate analysis, which included physico-chemical, sensory, and microbiological analyses of raw chicken meat. The analysis of the raw meat in the laboratory revealed inconsistent variations between the control and retail samples in terms of parameters, such as proximate composition, pH, the water-holding capacity (WHC), thiobarbituric acid (TBA), instrumental color analysis, and sensory evaluation. The moisture content of the control breast sample was significantly higher (p < 0.05) than that of the samples from shops 2, 3, and 5. However, it was statistically similar to that of the samples from shops 1, 4, and 6. The total plate and psychrotrophic counts of the control thigh sample were significantly lower than those of the samples from shops 3, 4, 5, and 6. Among the thigh pH values, the samples from shops 1, 2, 5, and 6 had significantly higher pH values than the control sample. The variations in the various parameters were multifactorial and established the superiority of birds slaughtered under laboratory conditions and grown in university farms compared to the raw chicken meat available in retail outlets in Hisar city.

Microbiological and physicochemical quality of tilapia fillets treated with ozone and chlorine solution and stored under refrigeration

Fish are foods of high nutritional value for the human diet. However, they deteriorate easily due to microbial activity. The combined action of sanitizing solutions on fillets, the antimicrobial and physicochemical effects of aqueous ozone and chlorine used to wash fillets were investigated immediately after application and during storage. The fillets were treated with demineralized water (control), 5 ppm chlorine solution (Cl), 5 ppm ozone solution (Oz) or 5 ppm chlorine solution with 5 ppm ozone (Cl+Oz). The proximate composition and pH of the fillets were not altered immediately after treatment. The mesophilic count decreased by 0.49 log CFU/g at Cl and 0.56 log CFU/g at Cl+Oz. The Cl treatment showed lower values of lipid oxidation, and the control and Cl treatments showed lower values for total volatile base nitrogen (TVB-N). The treatments did not differ from each other during storage; increases in lipids, TVB-N, lipid oxidation and mesophilic and psychrotrophic counts, as well as a reduction in proteins, were observed. These results were expected due to microbial degradation during storage. The results indicated that the combined action of the sanitizers regulated microbial activity better than the control but was not able to promote the shelf life of the product.