Total Volatile Basic Nitrogen Values Research Articles

Combined Effect of an Active AgIon® Absorbent Pad and a Chitosan Coating on the Preservation of Fresh Beef

In the present study, the combined effect of an AgIon® antimicrobial absorbent (Ζ) pad and a chitosan coating (C) on the preservation of fresh beef stored aerobically at 5 °C was investigated. Microbiological, physicochemical, and sensory attributes were monitored for up to 10 days of storage. The microbiological data indicated that the C and chitosan coating plus absorbent pad (CZ) treatments were the most efficient in reducing total viable counts (TVC) by 4.09 and 3.53 log cfu/g compared to the control W and Z treatments on day 4 of storage (p < 0.05). An analogous reduction in the counts of the other microbial groups monitored was recorded. pH values were ca. 5.7 for treatments W and Z and 5.45 for treatments C and CZ on day 4 of storage (p < 0.05). The total volatile basic nitrogen (TVB-N) values remained <20 mg/100 g for all treatments on day 4 and for treatments C and CZ on day 10 of storage. The total color difference values decreased (p < 0.05) during storage for treatments W and Z, but remained constant for treatments C and CZ. Based on sensory, microbiological and physico-chemical data, beef shelf life was ca ^# + 3 days for samples W and Z and at least 10 + 3 days for samples C and CZ. Between the two antimicrobial treatments, chitosan was considerably more effective than the AgIon® antimicrobial absorbent pad, which showed practically no antimicrobial activity in direct contact with beef meat.

Growth Reduction of Vibrionaceae and Microflora Diversity in Ice-Stored Pacific White Shrimp (Penaeus vannamei) Treated with a Low-Frequency Electric Field.

A novel storage technique that combines the low-frequency electric field (LFEF) and ice temperature was used to extend the shelf life of Pacific white shrimp (Penaeus vannamei). The study investigated the effect of LFEF treatment on the quality and microbial composition of Penaeus vannamei during storage at ice temperature. The results showed that the LFEF treatment significantly extended the shelf life of shrimp during storage at ice temperature. The total volatile base nitrogen (TVB-N) and pH of samples increased over time, while the total viable count (TVC) showed a trend of first decreasing and then increasing. Obviously, shrimp samples treated with LFEF had a lower pH, TVB-N and TVC values than the untreated samples (p < 0.05) at the middle and late stages of storage. LFEF treatment increased the diversity and altered the composition of the microbial communities in Penaeus vannamei. Additionally, the treatment led to a decrease in the relative abundance of dominant spoilage bacteria, including Aliivibrio, Photobacterium and Moritella, in Penaeus vannamei stored at ice temperature for 11 days. Furthermore, correlation analysis indicated that TVB-N and pH had a significant and positive correlation with Pseudoalteromonas, suggesting that Pseudoalteromonas had a greater impact on shrimp quality. This study supports the practical application of accelerated low-frequency electric field-assisted shrimp preservation as an effective means of maintaining shrimp meat quality.

The effect of carvacrol, thymol, eugenol and α-terpineol in combination with vacuum packaging on quality indicators of anchovy fillets

Food safety issues associated with the increased use of synthetic and chemicals preservatives agents are receiving increasing attention. The utilisation of natural resources may provide a potential and advisable alternative to chemical preservatives in the seafood industry. This research study focused on the impacts of pure bioactive compounds (carvacrol, thymol, eugenol, and α-terpineol) on the sensory and microbiological (total viable count, TVC) and chemical qualities (total volatile basic nitrogen (TVB-N) value, thiobarbituric acid (TBA), free fatty acid (FFA), and peroxide value (PV)) of vacuumed packaged anchovy (Engraulis encrasicolus) fillets during the refrigerated storage period. This study also evaluated the potential effect of bioactive compounds on biogenic amines (BAs) and ammonia (AMN) production in fish samples. Sensory investigations revealed that the control had an 8-day shelf life, that of the carvacrol and α-terpineol treatment was 15 days, and that of the thymol and eugenol treatment was 19 days. The application of bioactive compound on fish had a positive impact on the preservation of its oxidative stability through the reduction of TBA, FFA, and PV values as well as enhancement of the microbiological quality in comparision to the control. The use of pure bioactive compounds resulted in the reduction of the accumulation of BAs and AMN in anchovy fillets during 22 days of storage. The results exhibited that the pure bioactive compounds mainly eugenol and thymol, can increase the shelf life of anchovy. Therefore, they can be used by seafood industries as preservative agents due to their good antimicrobial and antioxidant activities.

Identification of the anthocyanin profile from Butterfly pea (Clitoria ternatea L.) flowers under varying extraction conditions: Evaluating its potential as a natural blue food colorant and its application as a colorimetric indicator

This study aims to extract anthocyanins from BPF (Butterfly Pea Flower) to determine an effective solvent combination resulting in higher total anthocyanin content. Various solvent combinations were utilized to discern crucial characteristics of the obtained BPFE (Butterfly Pea Flower Extract). The BPFE from the optimal treatment was utilized as a pigment in colorimetric indicators, which were then evaluated for their initial response to seafood spoilage stored at room temperature for 24 h. The color change response of the colorimetric indicators employing BPFE pigment was compared with the pH and TVBN (Total Volatile base Nitrogen) values of the seafood initially and after 24 h. The highest total anthocyanin content was achieved with the combination of 96% ethanol/1.5 N HCl (85:15, v/v) at 551.06 mg/L, followed by the combination of 96% ethanol/distilled water (70:30, v/v) with pH adjustment to 1 using 1.5 N HCl at 484.27 mg/L. Subsequent combinations, in decreasing order, were 96% ethanol/1.5 N HCl (99:1, v/v), 96% ethanol/distilled water (70:30, v/v), and lastly, 96% ethanol/distilled water (30:70, v/v), with total anthocyanin content of 275.53 mg/L, 200.39 mg/L, and 125.24 mg/L, respectively. BPFE applied in colorimetric indicators demonstrated responsiveness to seafood spoilage through color changes, with tested spoilage indicators being pH and TVBN. The initial (first hour) pH and TVBN values for each tested seafood were 5.5 and 9.42 mg/100 g (Scylla serrata), 6.4 and 4.23 mg/100 g (Litopenaeus vannamei), 5.4 and 11.29 mg/100 g (Uroteuthis sibogae), and 6.5 and 10.26 mg/100 g (Restrelliger kanagurta). Meanwhile, the pH and TVBN values after 24-h storage at room temperature became 7.9 and 57.01 mg/100 g, 7.4 and 76.65 mg/100 g, 7.5 and 216.44 mg/100 g, and 7.8 and 51.86 mg/100 g, respectively. The conclusion drawn is that the extraction of BPFE is more efficient when utilizing acidified ethanol solvent, and the resulting BPFE holds promise as a reliable pH indicator.

Quality evaluation of improved and traditionally dried Bombay duck (Harpodon nehereus) through biochemical, microbiological, and organoleptic analysis

The study was conducted to compare the quality and shelf life of traditionally dried (collected from the local markets) Bombay duck (Harpodon nehereus) with improved dried products (produced using a newly developed fish dryer) to assess its suitability. The quality of these products was evaluated through organoleptic, water reconstitution, nutritional, chemical, and microbiological characteristics. The organoleptic quality of improved dried fish was excellent while those produced traditionally were with grayish and dark brown color, rancid odor, and soft and fragile texture with insect infestation. The water reconstitution properties of the improved dried sample were 75.71% and 89.39% at room temperature and 80 °C, respectively, which were comparatively higher than the traditional dried products. The protein, ash, and contents were significantly higher in improved dried fish products while the lipid and total volatile base nitrogen (TVB-N) content were much lower than those of market-dried samples. The total viable counts (TVC) of bacteria were significantly higher in the traditional products which indicated poor quality. To find out the best storage method, dried fish was kept at three different conditions: in the open air at room temperature, in a sealed pack at room temperature, and a sealed pack at refrigeration temperature (4 °C). The shelf life of the products in different storage conditions was evaluated by estimating their moisture, protein, lipid, ash, TVB-N, and TVC values. The products kept at 4 °C temperature was found almost unaltered in terms of their nutritional properties after 4-months storage period. Results indicated that the newly developed fish dryer produced high-quality dried fish products with longer shelf life can be expected if the dried fish is stored at 4 °C refrigeration temperature. Our findings will be a valuable tool for the fish processors to ease the fish drying process and its storage that will enable them to commercially supply good quality dried Harpodon nehereus in the market chain at a low-cost.

Development of active packaging material based on polycaprolactone/hydroxypropyl methylcellulose nanofibers containing carbon dot nanoparticles for meat preservation

This work demonstrates the feasibility of using a combination of biodegradable polycaprolactone (PCL) and natural-based hydroxypropyl methylcellulose (HPMC) polymers containing carbon dots (CDs) for food packaging applications. CDs were synthesized using the insoluble portion of Zedo gum. The 5% and 15% concentrations of bare Zedo CDs (Z-CD) and nitrogen and sulfur co-doped CDs (TZ-CD) were chosen for incorporation into PCL/HPMC nanofibers (NFs). The PCL/HPMC/Z-CD15% and PCL/HPMC/TZ-CD15% demonstrated improved tensile strength (12.88 and 15.01 MPa), water solubility (30.20 and 42.36%), and water vapor transmittance (0.62 and 0.71 g mm/m2 h kPa)), respectively. When comparing the release of CDs in 10%, 50%, and 95% ethanolic solutions, it was found that TZ-CD released more rapidly than Z-CD from NFs in all three simulants. The CDs-added NFs exhibited potent antioxidant activity (80.5%). More significant antimicrobial activity against S. aureus was observed compared to E. coli. Additionally, reductions in total volatile basic nitrogen and thiobarbituric acid values indicated that beef covered with PCL/HPMC/TZ-CD15% and PCL/HPMC/Z-CD15% NFs had an extended shelf life of more than five days. In conclusion, PCL/HPMC/Z-CD15% and PCL/HPMC/TZ-CD15% NFs can be used as promising biodegradable packaging materials to enhance the shelf life of meat products.

Inhibition of protein denaturation and oxidation of prepared shrimp paste by sturgeon skin collagen peptide

This study investigated the cryoprotective effect of different concentrations (0.5%, 1.0%, 1.5%, 2.0%, and 2.5%) of sturgeon skin collagen peptides (CPs) on the changes in protein denaturation, oxidation, and overall quality of prepared shrimp paste during 180 d cryopreservation. Compared with phosphates and sorbitol, higher concentrations (>1.5%) of CPs minimized the denaturation and oxidation of protein with higher protein solubility, thermal transition enthalpy, and less carbonyl formation. Meanwhile, the decrease of hydrogen and ionic bonding was inhibited accompanied by less thawing loss and cooking loss. Compared with sorbitol, CPs at all concentrations contributed to less antioxidant effect in retarding the lipid oxidation after 180 d, however still exhibited lower thiobarbituric acid values than the control. The freshness of the 2.5% CPs group and sorbitol group was well maintained with the total volatile basic nitrogen value kept under 20 mg/100 g. Furthermore, a compact and less-aggregated gel matrix was observed during frozen storage. These findings indicate that CPs posed dose-dependent cryoprotective effects on shrimp paste, representing it as a comparable alternative to polyphosphates or sorbitol for seafood cryopreservation.

Fabrication of cucumber peel extract‐imbued dragon fruit peel pectin hydrogel packaging films: Assessment in preservation of chicken meat

AbstractWith plastic packaging posing severe risk on ecosystem, there is a crucial need for the development of sustainable and eco‐friendly packaging materials for food preservation. This work aims to develop cucumber peel extract imbued into dragon fruit peel pectin films for meat packaging. The cucumber peel extract and dragon fruit peel pectin were obtained by via the environmentally benign microwave‐assisted method. Incorporation of cucumber peel extract led to an enhancement in the density and thickness of the pectin thin films. In addition to improving the tensile strength, antioxidant potential, and opacity of the films, the water‐barrier properties were also augmented. Trials on chicken meat indicated lower pH changes, weight loss, and total volatile basic nitrogen (TVB‐N) values during the refrigerated storage tenure. Thus, our work paves the path for the design of a sustainable packaging for meat and simultaneously addresses the valorization of fruit peel wastes.Highlights Dragon fruit peel pectin, cucumber peel extract obtained by microwave method. Peel extract‐imbued pectin thin films were fabricated using polyethylene glycol (PEG) as plasticizer. Addition of peel extract enhanced the density and opacity of films. Films have good tensile strength, water‐barrier, and antioxidant properties. Chicken meat packaging suggested lower pH, weight loss, and TVB‐N values.

Effects of curing concentration and drying time on flavor and microorganisms in dry salted Spanish mackerel

This study investigated the quality changes of dry salted mackerel during curing and drying process and the relationship between flavor substances and microorganisms. The results showed that the thiobarbituric acid reactive substances (TBARS) values increased gradually with the increase of salt concentration and treatment time. The total volatile base nitrogen (TVB-N) values and total viable counts (TVC) values showed the same trend. Under 3% condition, the TVB-N values exceeded the standard and was not suitable for consumption. A total of 61 volatile flavor substances were identified by Gas chromatography-ion mobility spectrometry (GC-IMS), among which aldehydes contributed the most. Staphylococcus and Cobetia were the most abundant by High-throughput sequencing (HTS). There was significant correlation between TOP15 microorganisms and TOP20 flavor substances. Staphylococcus and Cobetia were positively correlated with 13 volatile flavor substances, which contributed to the formation of flavor in naturally fermented Spanish mackerel.

Effects of mango and partridge tea extracts on microbial, physical, and chemical properties of tilapia fillets treated with in-package cold plasma during refrigerator storage

Abstract Objectives The effect of natural extracts on the oxidative quality of cold plasma (CP)-treated tilapia fillets during 9 d refrigerator storage was explored by adding mango and partridge tea extracts as natural antioxidants. Materials and Methods The effects of mango and partridge tea extracts on the fish during storage were evaluated using the total viable count (TVC), total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substance (TBARS), carbonyl values, and color. Results The results showed that on the ninth day, the TVC of the mango extract (ME)-CP group was 3.52±0.08 log colony-forming units/g, which was significantly (P&amp;lt;0.05) lower than that of the other groups, while the TBARS of ME-CP and partridge tea extract (MOE)-CP was similar. The TVB-N values in the ME-CP and MOE-CP groups were 10.21±0.7 mg/100 g and 14.27±0.31 mg/100 g, respectively, which were within the acceptable values. The sulfhydryl and carbonyl contents in ME-CP were lower than those in MOE-CP; however, no significant variation was detected in texture. No significant changes were observed in the L* values among the treatment groups, while the b* values in the MOE-CP group were significantly increased (P&amp;lt;0.05). Conclusions Therefore, the addition of ME combined with CP treatment can inhibit microbial growth, lipid oxidation, and protein oxidation in tilapia fillets without significantly impacting their color.

Physico-Chemical and Sensory Assessment of Local and Imported Catfish Fillets

In this study, twenty fresh African catfish (Clarias gariepinus) and silver catfish (Bagrus bayad) fillets as well as twenty frozen pangasius catfish (Pangasianodon hypophthalmus) fillets were collected from Egyptian local markets and retailers during 2021. Pangasius catfish fillets can be divided into two grades: white basa fillets (grade I, white colour) and red basa fillets (grade II, pale pink to red colour). This study aimed to assess the physical (colour and shear force), chemical (pH, TVB-N and TBARS) and sensory parameters of catfish fillet samples. The sensory attributes of raw catfish fillets were measured using a 9-point hedonic scale and these attributes include colour and appearance, odor, texture, and overall acceptability. The results of the proximate composition showed that the African catfish and silver catfish fillets had significantly lower moisture (76.12-76.94) and higher crude protein (17.19-17.24) and fat levels (3.35-4.12) compared to the frozen Pangasius catfish fillets. The total volatile basic nitrogen (TVB-N) ranged from 6.83 to 16.38 mg/100g, thiobarbituric acid-reactive substances (TBARS) values ranged from 0.35 to 1.01 mg malonaldehyde/kg and pH ranged from 6.43 to 7.35. The TVB-N and TBARS values of examined catfish fillets were within acceptable limits. The African catfish fillets were darker and characterized by higher redness (a*) and lower yellowness (b*) values as well as higher shear force values (9.52 kgf/m3), while white basa fillet was the lowest darkness, less saturated with the red pigment (a*) and more saturated with the yellow component (b*) as well as lower shear values (2.17 kgf/m3) among the examined catfish fillets. African catfish and silver catfish fillets showed significantly higher sensory scores than the Pangasius catfish fillets. All the organoleptic properties of raw catfish fillets were above the rejection threshold score (≤4.0) In conclusion, catfish fillets were of superior quality and acceptable for human consumption.

Effect of Urtica dioica L. Essential oil (forms of free and nanoliposome) on some inoculated pathogens (Escherichia coli and Listeria monocytogenes) in minced camel meat

The goal of research was to investigate the impact of nanoliposome and free forms of nettle (Urtica dioica L.) essential oil (EO) on sensory, chemical and microbial properties of minced camel meat during storage at 4 °C. In our investigation, Listeria monocytogenes and Escherichia coli were inoculated into minced camel meat. The outcomes expressed the zeta potential, particle size, polydispersity index and efficiency of encapsulation of prepared nanoliposome were −17.5 mV to −12.8 mV, 143 to 158 nm, 0.77 ± 0.05 to 0.86 ± 0.07 Mw/Mn and 50.26–67.28 %, respectively. Also, according to the microbial analysis, the MIC of EO and nanoliposome-EO (N-EO) for E.coli was 25 ± 2.5 and 25 ± 2.1 mg/mL, respectively, and for L. monocytogenes was 12.5 ± 2.1 and 12.5 ± 2.1 mg/mL, respectively, and the MBC of EO and N-EO for L. monocytogenes was 50 ± 3.1 and 50 ± 3.2 mg/mL, respectively, and for E. coli was 50 ± 2.2 and 50 ± 2.2 mg/mL, respectively. The highest of 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assay were detected in the BHT 200 (94.7 ± 2.7 and 95.6 ± 3.2, respectively) and lowest of them were detected NEO1% (33.7 ± 12.2 and 22.37 ± 0.22, respectively). After 18 days, the minimum value of pH was identified in the N-EO 2 % group incubated with L. monocytogenes (with pH = 6.9) and E. coli (with pH = 6.87). Furthermore, after 18 days of storage, the minimum TVB-N (total volatile basic nitrogen) value was observed in the N-EO group (26.89 mg N/100 g) and the maximum TVB-N value was observed in the control group (33.78 mg N/100 g). Finally, the N-EO and control treatment (during the experiment) had the highest and lowest sensory evaluation score, respectively. Finally, the N-EO group got a highest sensory score, whilst the group of control got the lowest acceptance score, after 18 days of storage. Based on the outcomes obtained from this research, using nettle (Urtica dioica L.) EO (in nanoliposome form) increases the storing time of minced camel meat.

Sensorial, physicochemical and microbial quality evaluations of sun-dried marine fishes available in the Bay of Bengal of Bangladesh

The present study aimed to assess the sensory, physicochemical, and microbiological quality of five sun-dried marine fish (White sardine- WS, Longjaw thryssa- LT, Doublespotted queenfish- DQ, Chinese pomfret- CP, and Indian threadfin- IT) species (500 gm of each species) collected from Nazirartak fish drying center of Cox's Bazar district, Bangladesh at the month of April 2023. Physical (pH and water reconstitution), biochemical (proximate composition, peroxide value, acid value, conjugated diene and total volatile basic nitrogen), microbiological (total plate count, Escherichia coli, Salmonella sp. and Vibrio sp.) and sensory properties and score revealed that WS showed comparatively better quality than LT, DQ, CP, and IT. pH value and water reconstitution ability of sun-dried WS showed comparatively more acceptable. Significantly (p<0.05) the moisture, protein, lipid, and ash content of those dried fish products were varied from 18.57±0.41% (WS) to 20.38±0.41% (DQ), 59.38±1.05% (DQ) to 61.51±0.53% (WS), 7.61±0.37% (DQ) to 9.68±0.31% (WS), and 9.96±0.27% (LT) to 11.98±0.65% (DQ), respectively. On fresh matter basis, the highest total volatile basic nitrogen value was observed in CP (54.22 mg/100g), while the lowest value was found in WS (29.77 mg/100g). Moreover, sun-dried WS had the lowest peroxide value, acid value, and conjugated diene considered good acceptance. Only WS was deemed more safer and more suitable for human consumption based on total plate count and total Vibrio sp. count. All of the sun-dried fishes were free of the pathogenic bacteria such as E. coli and Salmonella sp., with the exception of CP and IT, where the total E. coli and Salmonella sp. count values were found 2.84 log CFU/g and 3.06 log CFU/g for both species, respectively. Taken together, White sardine (Escualosa thoracata) was found highly acceptable for human consumption based on sensory, physicochemical, and microbial analysis. It has been recommended that elevated focus on processing, handling, hygiene, and storage is crucial to meet consumer expectations of these dried fishery products.

Effects of rosehip sauce on chemical, oxidative and sensorial quality of marinated anchovy (Engraulis Encrasicolus Linnaeus, 1758)

Marinated anchovies are of economic importance in Turkey. However, natural antioxidants affecting quality of marinated anchovies are rarely addressed. The purpose of this study is to compare olive oil and rosehip sauce as fillers in anchovy marinades. The study investigated the effects of rosehip sauce on the quality of marinated anchovies stored at 4°C. Anchovy were marinated with 4% acetic acid and 12% NaCl, put into plastic jars, filled with either olive oil or rosehip sauce and stored at 4°C. Changes in sensory attributes were determined during the process, and the following chemical parameters were monitored: total phenolic content (mg/100 g GAE), total volatile basic nitrogen (mg/100 g), pH, peroxide value (meq/kg) and thiobarbituric acid (mg MDA/kg). Values of total volatile basic nitrogen (TVB-N), peroxide value (PV) and thiobarbituric acid (TBA) increased during the storage. Higher values of TVB-N, TBA and PV were found in samples with olive oil than those with rosehip sauce. Samples with rosehip sauce demonstrated better oxidative stability. Rosehip sauce samples had higher appearance, odor, color and texture scores than olive oil samples.

Chitosan composite films based on tea seed oil nano-microcapsules: Antibacterial, antioxidant and physicochemical properties

The use of nanotechnology has contributed to conquer the disadvantages of oil-loaded food packaging by altering their properties. In this study, chitosan (CS) composite films were fabricated using a novel nano-encapsulation system: ethanol extract of propolis (EEP)-phosphatidylcholine (PC)-tea seed oil (TSO) nano-microcapsules. X-ray diffraction results indicated that the nano-microcapsules were biocompatible with CS. Uniformly dispersed EEP-PC-TSO nano-microcapsules in CS improved the UV-blocking ability, thermal stability, structural densification, yellowing, and water vapor permeability of the composite films, the release of TSO occurs gradually and under controlled conditions. Compared with a simple mixture film of CS/PC/TSO/EEP, the CS film based on nano-microcapsules containing EEP-PC-TSO was more effective at reducing total bacterial count, thiobarbituric acid reactants (TBARS), and total volatile basic nitrogen (TVB-N) values, extending the shelf life of pork tenderloin. In summary, this CS composite film based on EEP-PC-TSO nano-microcapsules could be applied as a potential preservative film for food packaging.

Characterization, antioxidant, and sausage preservation effects of ethanol extract from lotus seed peel powder

The ethanol extract from lotus seed peel powder (EEL) were characterized, and its antioxidant and sausage preservation effects were investigated in this study. Chemical composition, UV and FTIR spectra of EEL, 70% ethanol-soluble matter (70-DF), and precipitate (70-PF) showed similar trends to some extent, indicating their similar chemical composition. Then, their antioxidant potentials were confirmed that EEL exhibited stronger DPPH· scavenging capacity, FRAP, and lipid peroxidation inhibitory activities than those of 70-DF and 70-PF. Correlation analysis also indicated phenolics as the main antioxidant components of EEL. Hence, catechin, epicatechin, rutin, phlorizin, and gallic acid were identified as the dominant phenolics of EEL. Throughout the chopping, roasting, cooking and pasteurization processes, EEL could protect the color, maintain the pH value, and decline the total volatile base nitrogen (TVB-N) and thiobarbituric acid reactive substances (TBARS) values of sausages. Following 18 days of storage at 25 °C, supplementation with EEL reduced the TVB-N and TBARS values of sausages, while pH value showed an opposite trend. The present study found that EEL could prolong the shelf life of sausages via inhibiting the oxidation of lipids and proteins, which would promote the utilization of lotus seed peel powder as a substitute for nitrites to preserve meat products.

Impact of supercooling storage on physical and chemical properties of yellowfin tuna (Thunnus albacares)

Seafood is highly perishable, and its spoilage begins immediately after harvesting due to the production of various metabolites. However, freezing, a conventional long-term preservation technology, causes quality degradation due to ice crystallization. Supercooling has emerged as a promising technique to prevent ice formation and quality degradation. In this study, tuna fillets were supercooled at −3.5 °C with an external pulsed electric field (PEF) and oscillating magnetic field (OMF) strengths for optimization. Quality factors such as drip loss, color, microbial analysis, texture, and total volatile basic nitrogen (TVB-N) were evaluated in comparison with refrigerated, frozen-thawed, and supercooled samples stored for 1, 4, 7, and 10 days. The results showed that supercooled samples had lower TVB-N values than refrigerated samples. The aerobic plate counts of supercooled tuna samples did not significantly vary from 1 to 7 days of storage. Moreover, supercooling preserved the textural integrity of the product and reduced drip loss compared to frozen-thawed samples. Therefore, supercooling preservation can extend the shelf-life of tuna fillets while minimizing quality degradation, indicating its potential compared to conventional refrigeration and freezing methods.

Effects of Potassium Bicarbonate on Gel, Antioxidant and Water Distribution of Reduced-Phosphate Silver Carp Surimi Batter under Cold Storage.

The changes in storage loss, water distribution status, gel characteristics, thiobarbituric acid reactive substances (TBARSs), total volatile basic nitrogen, and total plate count of cooked reduced-phosphate silver carp surimi batter during cold storage at 4 °C were investigated. The storage loss, content of free water, pH, hardness, TBARSs, total volatile basic nitrogen value, and total plate count of all cooked silver carp surimi batters significantly increased (p < 0.05) with an increase in cold storage time. Meanwhile, the content of immobilized water, whiteness, springiness, and cohesiveness significantly decreased (p < 0.05). At the same cold storage time, the sample of cooked reduced-phosphate silver carp surimi batter had lower water mobility, darker color, and better texture characteristics than the cooked silver carp surimi batter without potassium bicarbonate; however, the values of TBARSs, total volatile basic nitrogen, and total plate count were not significantly different (p > 0.05). This meant that there was no difference between potassium bicarbonate and sodium tripolyphosphate in antioxidant and antibacterial activity during the cold storage of silver carp surimi batter. To summarize, the use of potassium bicarbonate instead of sodium tripolyphosphate could produce cooked reduced-phosphate silver carp surimi batter with better water-holding capacity and gel characteristics during cold storage.

The effect of essential oil of Anethum graveolens L. seed and gallic acid (free and nano forms) on microbial, chemical and sensory characteristics in minced meat during storage at 4°C.

The aim of this study was to evaluate the effect of gallic acid (GA) and essential oil (EO) of Anethum graveolens L. seed (forms of nanoliposome and free) on bacteriological, chemical and sensory properties of minced meat during storage. In this research, Escherichia coli (gram negative) and Staphylococcus aureus (gram positive) were used to examine the effect of these compounds on meat. The particle sizes (z-average diameter) of prepared nanoliposomes of EO and GA were in the range of 141 to 165nm and 146-160nm, respectively and the efficiency of encapsulation (EE %) in the current research was 51.76-69.8% in nano EO (NEO) and 53.23-67.07% in nano gallic acid (N-GA). Also, the outcomes indicated the treatment containing nano-liposomes had a better antimicrobial effect in both of bacteria. In present study, the Minimum Inhibitory Concentration (MIC) of GA, N-GA, EO and NEO for S. aureus was 0.62±0.01, 0.62±0.02, 0.62±0.01 and 0.62±0.01mg/mL, respectively, and for E. coli was 0.62±0.01, 0.62±0.01, 1.25±0.1 and 1.25±0.1mg/mL, respectively. Also, the results showed MBC (The Minimum Bactericidal Concentration) of GA, N-GA, EO and NEO for S. aureus was 0.62±0.02, 0.62±0.03, 1.25±0.1 and 1.25±0.1mg/mL, respectively, and for E. coli was0.62±0.01, 1.25±0.1, 2.5±0.2, 2.5±0.2mg/mL, respectively. The highest and lowest of 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging were detected, in the Butylated hydroxytoluene (BHT) 200 and EO1%, respectively. Furthermore, after 18day, minimum pH and Total volatile basic nitrogen (TVB-N) value were related to the N-GA2% on S. aureus with pH=6.5 and NEO group (27mgN/100g), respectively. Finally, the treatment of NEO showed a higher acceptance score of sensory evaluation after 18days. According to the outcomes of current investigation, the use of nanocapsulated EO and GA are effective (as a coating for food storage) and can increase the shelf life of minced meat.

Quality Changes in Intermediate Flying Fish, Cheilopogon intermedius Parin, 1961, During Ambient and Ice Storage

Intermediate flying fish, Cheilopogon intermedius, Parin, 1961, is a popular source of inexpensive animal protein in the Philippines, but it remains susceptible to deterioration during processing. The study evaluated the sensory, microbiological, and physico-chemical characteristics of flying fish, C. intermedius stored at ambient conditions (27– 29 °C) and on ice (1–2 °C) storage. The storage duration of flying fish was 8 h at ambient temperature and around 12 days in ice. A ten-member taste panel rejected raw fish due to strong fishy to sour odours and soft texture. Similarly, cooked samples were rejected based on sour and ammoniacal odours, mushy texture, and a bitter taste. Results of sensory evaluation correlated with those of microbial and chemical analyses. Bacteria multiplied rapidly at ambient temperature with values of 11.05 log CFU.g-1 and 7.55 log CFU.g-1 (P &lt; 0.05) for total viable count (TVC), and H2Sproducers count, respectively, at the end of the 20-h storage. In comparison, bacterial counts remained below rejection limits until the end of the storage period for samples stored in ice. Total volatile base nitrogen (TVB-N) and trimethylamine nitrogen (TMA-N) accumulated rapidly at ambient temperature, reaching 86.86 mg.100 g-1 and 35.65 mg.100 g-1, respectively, at the end of the storage period. In ice, TVB-N, TMA-N, and histamine values were slowed down, reaching rejection limits only at the end of the storage period. Moreover, the K value increased linearly at ambient storage, while a gradual increase was observed for samples stored in ice. Therefore, without the application of adequate icing, flying fish would undergo rapid decomposition at ambient temperature.