Volatile Basic Nitrogen Content Research Articles

Determination of Total Volatile Basic Nitrogen (TVB-N) Content in Beef Based on Airflow and Multipoint Laser Technique

Determination of Total Volatile Basic Nitrogen (TVB-N) Content in Beef Based on Airflow and Multipoint Laser Technique

Application of a Newly Developed Chitosan/Oleic Acid Edible Coating for Extending Shelf-Life of Fresh Pork.

This study aimed at evaluating the applicability of a newly-developed chitosan/oleic acid edible coating for extending the shelf-life of fresh pork under aerobic-packaging conditions. Various coating formulations were used: 2% chitosan alone (CHI), 0.5% (v/v) oleic acid in 2% chitosan (CHI/0.5%OA) and 1% (v/v) oleic acid in 2% chitosan (CHI/1%OA) were prepared. For coating, fresh pork slices were fully immersed in the coating solutions for 30 s and dried naturally at 4 °C for 30 min. The coated samples were placed on trays, over-wrapped with plastic film, stored at 4 °C for 21 days, and were analyzed for shelf-life stability. Samples without coating were used as control. It was found that the aerobic bacteria and Pseudomonas spp. counts, and total volatile basic nitrogen (TVBN) content were almost two to three times lower in the CHI/OA-coated samples compared to the control after 21 days of storage (p < 0.05). The CHI/OA coating combination completely inhibited growth of E. coli, and protected the meat from discoloration after 21 days of storage. In particular, the addition of OA increased the concentration of volatiles associated with pleasant aromas. This study provides an application potential of chitosan/oleic acid edible coating in preservation of fresh pork to prolong the shelf-life and improve safety.

큰가리비 보일드통조림의 제조 및 품질특성

This study was carried out to investigate the quality characteristics of canned boiled scallop. Three types of canned products were prepared as Sample-1 (Canned boiled scallop in salt solution), Sample-2 (Canned boiled scallop in bamboo salt solution) and Sample-3 (Canned boiled scallop in salt and bamboo salt mixture solution). After shucking and washing raw materials, then dehydrating at room temperature for 3 minutes, 40 g of scallop meat was filled into cans (301-1) added with additive material 50 mL (Sample-1; 2% salt solution, Sample-2; 1.7% bamboo salt solution, Sample-3; 1.9% salt and bamboo salt mixture solution), respectively. All samples were seamed by using vacuum seamer, and then sterilized to F0 value 10 min at 118°C in a steam system retort. There was no significant difference in moisture, crude protein, crude lipid, ash and volatile basic nitrogen (VBN) content among the samples. Salinity were 0.7, 1.2 and 0.9 g/100 g, respectively. The total amino acids content was the highest in the Sample-2 in which the major amino acids were glutamic acid, aspartic acid and glycine in all samples. In the sensory evaluation of the canned boiled scallop, Sample-3 had the highest scores in the items of taste and overall acceptance.

Assessment of chicken thigh meat quality of Ross 308 broiler of animal welfare certified farm

This study aimed to evaluate the difference in the thigh meat quality of Ross 308 broiler from conventional and welfare farms. Thigh meat samples of Ross 308 broilers (age, 35 d; carcass weight, 1.1 kg) from conventional farm (RCF, n = 60) and animal welfare farms (RAWF, n = 60) were analyzed. Proximate composition, pH, color (lightness, redness, and yellowness), water-holding capacity (WHC), shear force, total aerobic bacteria (TAB), and volatile basic nitrogen (VBN) were measured and the levels of bioactive compounds such as dipeptides (anserine and carnosine), creatine, creatinine, and their anti-oxidation activity were determined. The RCF and RAWF did not differ significantly in their proximate composition, WHC, color, and creatine and carnosine levels. The pH value was significantly lower in RAWF than in RCF on day 7. The shear force value was significantly higher in RAWF than in RCF throughout the storage duration. TAB in RCF on day 9 were significantly higher than those in RAWF. The VBN content of RAWF was significantly lower than that of RCF after 5 days of storage. Creatinine content was significantly higher in RAWF (3.50 mg/100 g) than in RCF (3.08 mg/100 g) on day 1. Along with higher carnosine and anserine contents of RAWF, it had significantly higher 2,2-diphenyl-1-picrylhydrazyl and 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) radical scavenging activities than those of RCF. These results imply that the animal welfare farming system beneficially affects the overall oxidative stability of Ross 308 thigh meat.

Effects of Modified Atmosphere Packaging with Different Gas Ratios on the Quality Changes of Golden Pompano (Trachinotus ovatus) Fillets during Superchilling Storage.

The quality changes of golden pompano fillets in air packaging (AP) and modified atmosphere packaging (MAP) with 30% CO2/70% N2, 50% CO2/50% N2, and 70% CO2/30% N2 were evaluated under superchilling (−3 °C). The results showed that the whiteness of fillets decreased during storage. The rate of pH increase of MAP was significantly slower than in AP groups, in which MAP with 70% CO2/30% N2 effectively suppressed the PH. Interestingly, the hardness decreased on day five following the treatments, followed by a relatively stationary trend. MAP could greatly suppress the increase of total volatile basic nitrogen (TVB-N) contents of fillets compared to fillets packed in AP. All MAP groups of fillets maintained first-grade freshness throughout storage, while the AP samples decreased to second-grade freshness on about the 25th day. MAP with 70% CO2/30% N2 and MAP with 50% CO2/50% N2 had the best results in inhibiting protein degeneration and explanation. Unexpectedly, drip loss of fillets in MAP far exceeded the AP group during storage, which causes sensory discomfort. Anaerobic plate count (APC) of fillets in AP exceeded the consumption limit of 6.7 log CFU/g on day 26 (6.75 log CFU/g on the 26th day), whereas the MAP was still microbiologically acceptable after 30 days of storage (6.43, 6.41, 6.22 log CFU/g, respectively). Considering physicochemical and microbiological parameters, the shelf life of fillets packed in AP was 25 days. MAP treatments could prolong the shelf life of fillets by ~4–5 days compared to AP. Overall, MAP with 70% CO2/30% N2 gas ratio was best for inhibiting the quality deterioration of fillets. Furthermore, principal component analysis (PCA) was performed to evaluate the critical indicators of quality deterioration of the fillets. Two principal components were determined by dimensionality reduction, in which the contribution of the first principal component was centrifugal loss > hardness > TVB-N > APC > CO2 solubility > TBARs > drip loss > pH, which mainly reflected the degree of microbial proliferation, protein hydrolysis, and oxidation. The contribution of the second principal component was pH > TBRAs > drip loss > APC > CO2 solubility > TVB-N > hardness > centrifugal loss, indicating a high correlation between lipid oxidation and microbial proliferation index.

Non-destructive determination of beef freshness based on colorimetric sensor array and multivariate analysis

Rapid and reliable detection of beef freshness is essential for diet safety and resource-saving. In this study, the colorimetric sensor array (CSA) integrated with whale optimization algorithm (WOA) and back-propagation neural network (BPNN) had been innovatively developed for the quantitative determination of beef freshness, regarding the total volatile basic nitrogen (TVB-N) and total viable counts (TVC) contents. Firstly, the CSA comprising twelve color-sensitive dyes was designed to acquire the scent fingerprints (RGB triplets) during beef storage. Secondly, WOA-BPNN was used to optimize the color components combination from the preprocessed CSA to acquire the dominant color components. Finally, the BPNN models were constructed based on the optimized color components, with the BPNN topology of 8–12–1 for TVB-N prediction and 6–6–1 for TVC prediction. The results revealed that the BPNN model combined with optimized color components could be utilized to quantitatively determine beef freshness. The overall results demonstrated that the CSA integrated with appropriate multivariable analysis methods could realize rapid and reliable quantitative determination of beef freshness. Furthermore, the WOA-BPNN could effectively extract the dominant color components, which was beneficial for improving detection accuracy and robustness of the BPNN, as well as time- and cost-saving.

Optimization of antibacterial and physical properties of chitosan/citronella oil film by electrostatic spraying and evaluation of its preservation effectiveness on salmon fillets

Response surface methodology was applied to optimize the effect of different concentrations of chitosan (CH), citronella oil (CNO) and surfactant tween 80 (TW) on antibacterial and physical properties of edible films prepared by electrostatic spraying (ES). In addition, the preservation effectiveness of the optimal formulation (OF) on salmon fillets was evaluated over a 10-day storage at 4 °C. Physicochemical and microbiological properties of salmon fillets were analyzed during storage. Results showed that TW contributed to the decrease of droplet size during ES, and antibacterial property was mainly attributed to CNO. The OF were obtained at CH concentration of 0.50%, CNO concentration of 0.50% and TW concentration of 0.30%, which improved the storage quality of salmon fillets (P < 0.05). The total number of bacteria of the uncoated salmon sample was 6.42 log CFU/g at day 10, while the value of OF treated group was 4.78 log CFU/g. The thiobarbituric acid (TBA) and total volatile basic-nitrogen (TVB-N) contents of the OF treated samples were only 38.4% and 48.6% of the values of the control sample, respectively. The OF treated group also retains better hardness and color at the end of storage. It was indicated that CH-essential oil coating applied by ES was effective for the preservation of salmon fillets.

Exploring the Fungal Community and Its Correlation with the Physicochemical Properties of Chinese Traditional Fermented Fish (Suanyu).

Suanyu is a traditional natural fermented fish product from Southwest China that contains very complex microflora. The main purpose of this study was to explore the fungal community and its relationship with the physicochemical properties of Suanyu. The fungal community structure of Suanyu from the main provinces (Guizhou and Hunan) was studied via high-throughput sequencing. The correlation between dominant fungi and physicochemical characteristics was analyzed via Spearman’s correlation coefficient. The results showed that the pH value, total volatile base nitrogen content, and thiobarbituric acid reactive substance content ranges of Suanyu samples were 4.30–5.50, 17.11–94.70 mg/100 g, and 0.61 to 3.62 mg/kg, respectively. The average contents of total volatile base nitrogen, thiobarbituric acid reactive substance, and total BAs in Suanyu from Guizhou were lower than those from Hunan. The main BAs were phenethylamine, putrescine, cadaverine, histamine, and tyramine. Ascomycota was the dominant fungal phylum, and Kodamaea, Debaryomyces, Wallemia, Zygosaccharomyces, and unclassified Dipodascaceae were the dominant fungal genera in different samples. Moreover, high abundance levels of Kodamaea and Zygosaccharomyces were found in Suanyu from Guizhou. According to the correlation analysis, Kodamaea and Zygosaccharomyces were negatively correlated with TBARS (R2 = −0.43, −0.51) and TVBN (R2 = −0.37, −0.29), and unclassified Dipodascaceae was significant negatively correlated with tyramine (R2 = −0.56). This study expands the understanding of the fungal community and the fermentation characteristics of the dominant fungi in Suanyu.

Effects of Gamma Irradiation on Inhibition of Urease Activity and Fishy Smell in Mackerel (Scomber japonicus) during Refrigerated Storage.

In this study, gamma-irradiated mackerel (Scomber japonicus) meat was stored in a refrigerator for 20 days to examine the physicochemical changes related to fishy smell. The effect of gamma irradiation on the inhibition of the activity of crude urease extracted from Vibrio parahaemolyticus was also evaluated. Increased levels of trimethylamine (TMA) and volatile basic nitrogen (VBN) content, which are the main components causing fishy smell, were significantly reduced by day 20 of storage after gamma irradiation, indicating that freshness was maintained during storage. The ammonia nitrogen contents of 3, 7, 10, and 20 kGy gamma-irradiated groups were significantly decreased by 6.5, 15.2, 17.4, and 23.9%, respectively, compared to non-irradiated groups on day 20 of storage. In addition, urease activity decreased in a gamma irradiation intensity-dependent manner. Volatile organic compounds (VOCs) were measured during the storage of gamma-irradiated mackerel meat. The contents of ethanol, 2-butanone, 3-methylbutanal, and trans-2-pentenal, which are known to cause off-flavors due to spoilage of fish, were significantly reduced by day 20 of storage. Therefore, gamma irradiation can be considered useful for inhibiting urease activity and reducing fishy smell during fish storage.

Combination of airflow and multi-point laser ranging technique for the prediction of total volatile basic nitrogen content in beef

Combination of airflow and multi-point laser ranging technique for the prediction of total volatile basic nitrogen content in beef

Inhibitory Effects of High-Hydrostatic-Pressure Processing on Growth and Histamine Formation of Histamine-Forming Bacteria in Yellowfin Tuna Meat during Storage.

Simple SummaryHigh-hydrostatic-pressure treatment effectively inhibited the growth and histamine formation of histamine-forming bacteria species in tuna meat during storage at low temperatures. Our findings can be used to enhance food safety and decrease the risk of histamine poisoning associated with consumption of tuna meat products.In the research, we evaluated the effects of high-pressure processing (HPP) on the growth and histamine formation of histamine-forming bacteria (HFB) in yellowfin tuna meat during storage. Tuna meat samples inoculated with the individual HFB species Morganella morganii and Photobacterium phosphoreum were subjected to HPP treatment at 250, 350, 450, and 550 MPa for 5 min, and the changes in bacterial count, total volatile basic nitrogen (TVBN) content, pH, and histamine content during storage at 4 and 15 °C were analyzed. The results indicate that the bacterial counts of the HFB species decreased significantly with increasing pressure, and HFB became undetectable in the samples treated at 450 and 550 MPa. At a storage temperature of 15 °C, the bacterial counts of both HFB species in the control group and samples subjected to HPP treatment at 250 and 350 MPa increased significantly with storage time. The bacterial counts of M. morganii in the samples stored at 4 °C decreased, whereas those of P. phosphoreum increased gradually owing to its psychrophilic nature. HPP treatment (>250 MPa) inhibited the increases in pH and TVBN content of the samples stored at 15 °C and delayed histamine formation in the samples during storage; these effects were more significant as the pressure during HPP treatment was increased.

Inactivation of Salmonella in steamed fish cake using an in-package combined treatment of cold plasma and ultraviolet-activated zinc oxide

An intervention technology combining in-package atmospheric discharge cold plasma (CP) treatment with ultraviolet (UV)-activated zinc oxide (ZnO) treatment was developed to decontaminate steamed fish cakes in commercial plastic packages. Efficacy of the simultaneous treatment of UV-activated ZnO treatment and CP treatment (ZnO&CP treatment) in inactivating Salmonella (1.8 log CFU/g) did not differ significantly from that of the CP-only treatment (P > 0.05). The CP treatment immediately after UV-activated ZnO treatment (ZnO-CP treatment) led to higher inactivation of Salmonella (2.4 log CFU/g) than the ZnO-only (0.4 log CFU/g) or CP-only (1.7 log CFU/g) treatments. Inactivation of Salmonella by ZnO-CP treatment increased as the ZnO or CP treatment time increased, the number of samples in the package decreased, and upon shaking the package during the CP treatment. The difference in Salmonella counts between ZnO-CP treated and untreated samples were maintained at 1.3–1.8 log CFU/g and 1.1–1.6 log CFU/g when samples were stored at 4 °C and 10 °C for 21 days, respectively. The ZnO-CP treatment did not alter the moisture content, water activity, color, pH, and gel strength of the steamed fish cake at both storage temperatures. However, the ZnO-CP treatment reduced the total volatile base nitrogen content in the steamed fish cake stored at 10 °C. These results demonstrated the potential of applying a combined treatment approach for microbial decontamination of steamed fish cake in plastic packages.

Effect of chitosan/starch aldehyde-catechin conjugate composite coating on the quality and shelf life of fresh pork loins.

Fresh pork is susceptible to oxidation and spoilage. Edible coating containing antioxidant and antimicrobial agents can create moisture and oxygen barriers around pork and inhibit oxidation and microbial growth in the pork. In this study, chitosan in combination with starch aldehyde-catechin conjugate (SACC) was used as a novel edible coating material for preserving fresh pork loins at chilled storage (4 ± 1°C) for 14 days. Effect of chitosan/SACC composite coating on the quality of pork loins including weight loss, colour, pH value, microbial spoilage, lipid oxidation, protein oxidation, texture and sensory attributes during chilled storage was determined. Chitosan and SACC had synergistic antioxidant and antimicrobial actions. As compared with uncoated and chitosan coated pork loins, chitosan/SACC coated pork loins showed lower weight loss (7.16%), pH value (5.99), total viable count (7.11 log CFU g-1 ), total volatile base nitrogen content (130.2mg kg-1 ), lipid oxidation level (0.47 mg malondialdehyde kg-1 ), protein oxidation level (0.047 mmol free thiol group g-1 ) and shear force (27.40 N) on day 14. Meanwhile, chitosan/SACC composite coating effectively maintained the colour, micro-structure and sensory attributes of pork loins throughout chilled storage period. The shelf life of pork loins was extended from 8 days (uncoated samples) to 14 days by chitosan/SACC composite coating. Chitosan/SACC composite coating effectively retarded the oxidation and spoilage of pork loins during chilled storage. © 2022 Society of Chemical Industry.

Changes in Quality Characteristics of Crassostrea gigas Oysters during Hypothermic Storage

Now oysters are one of the most common representatives of aquaculture grown worldwide. Finding reliable ways to assess the quality of oysters is an important task for breeding professionals and users of these products. The Food and Agriculture Organization considers microbiological testing and organoleptic parameters as mandatory tests for evaluation of the mollusks’ safety. We believe these parameters in oysters are insufficient for unbiased evaluation of the condition of mollusks. In this research, we attempted to determine the most sensitive indices of oysters’ viability during hypothermic storage under anoxia conditions. We investigated the oysters during 6 days of their storage in a household refrigerator at a temperature of 5°C. According to microbiological studies, during the experiment, we expected a rise in the total number of microorganisms. However, there was a paradoxical situation when at the end of the observations the total number of microorganisms decreased significantly, which contradicted the negative assessment of the state of oysters by organoleptic parameters. Flow cytometry studies also showed no correlation between the percentages of necrotized and apoptotic cells to organoleptic parameters. Studies have shown that on day 3 of storage, the oysters demonstrated a partial deterioration in organoleptic characteristics, which is clearly reflected in the content of volatile basic nitrogen in the tissues of mollusks, which characterizes the protein breakdown and accumulation of toxic nitrogen compounds. Thus, the content of volatile basic nitrogen in the tissues of oysters is the most sensitive and significant parameter in terms of biosafety of mollusks.&#x0D; Keywords: hypothermic storage, oysters, microbial flora, food quality, nitrogen

The Quality Analysis and Deterioration Mechanism of Liquid Egg White during Storage

The quality of liquid egg white (LEW) during storage is critical for the development of the egg industry. In order to effectively control its storage quality, the effects of packaging materials and storage conditions on the quality of LEW were investigated. High-throughput sequencing (HTS) was applied to explore changes in bacterial population proportions and microflora in the spoilage of LEW. The shelf life of LEW packaged with glass (LEW-PG), plastic (LEW-PP), and tinplate (LEW-PT) was preliminarily determined to be 8, 5, and 7 days, respectively. LEW-PG possessed superior sensory scores (65) and L values (87.5), and a lower growth rate of total volatile basic nitrogen (TVB-N) content among the three samples on the last day of shelf life, and was chosen for further study. During 24 days of storage, the sensory scores of the LEW-PG in 10 °C and 4 °C groups decreased by 32.7% and 25.7%, respectively. There was no significant difference in foaming properties of LEW-PG between the 10 °C and 4 °C groups (p &gt; 0.05). HTS analysis showed that the abundance of species composition in the 10 °C samples was higher than that in the 4 °C samples, though the latter possessed a higher community diversity. At the genus level, the dominant bacteria in the 10 °C group were Pseudomonas (21.79%), others (19.21%), and Escherichia (11.21%), while others (37.5%), Escherichia (30.40%), and Bifidobacterium (17.72%) were highly abundant in the 4 °C samples. It is hoped that this study could provide theoretical support for quality control of LEW during storage.

Colorimetric Biosensor Based on Magnetic Enzyme and Gold Nanorods for Visual Detection of Fish Freshness.

Histamine, an important safety index for aquatic products, can also be used as a freshness indicator for red-fleshed fish. In this work, magnetic graphene oxide (Fe3O4@GO, MGO) was applied to immobilize diamine oxidase (DAO) through a method of adsorption and covalent bonding. Under the optimized conditions, magnetic DAO prepared by adsorption immobilization had a higher enzyme activity than that of free enzyme, which was selected for the sensor construction. A colorimetric biosensor based on magnetic DAO induced etching of gold nanorods (AuNRs) was developed for the detection of histamine in fish. The developed biosensor showed an excellent response toward histamine with a low detection limit of 1.23 μM and had negligible interference from other diamines. With increasing the histamine concentration, the AuNRs after the reaction exhibited colors ranging from dark green to blue-green, blue, purple, red, and colorless. The etching induced multicolor change of AuNRs indicated the presence of different contents of histamine in mackerel during storage, and was consistent with the overall change in the content of the total volatile basic nitrogen (TVB-N). Thus, it was indicated that the proposed colorimetric biosensor with a naked-eye-detectable readout has a great potential to evaluate the freshness of red-fleshed fish high in histamine.

Evaluation of physicochemical properties and microbial counts of raw and cooked low‐fat patties added with eggplant powder prepared with different drying methods

SummaryEffects of different drying methods and different addition levels of eggplant (EP) on product quality of low‐fat patties (LFPs) were investigated during storage. EP was dried in an oven dryer at 60 °C or a freeze dryer at −50 °C. LFPs were prepared by replacing with 1.5% soy protein isolate (SPI). Six treatments were used in this study: (1) control (CTL), without addition of EP; (2) reference (REF), 0.1% ascorbic acid; (3) O1, 0.25% oven‐dried (OD) EP; (4) O2, 0.5% ODEP; (5) F1, 0.25% freeze‐dried (FD) EP; and (6) F2, 0.5% FDEP. Redness (a*) and lightness (L*) values in LFPs added with EP were lower than those of others (p &lt; 0.05) and decreased with increasing storage time. Yellowness (b*) values of cooked patties were increased during storage time (p &lt; 0.05), with control having the highest value. The addition of EP or ascorbic acid into LFPs lowered microbial counts than control (p &lt; 0.05). Thiobarbituric acid reactive substances (TBARS) was increased during storage, with REF having the lowest value, and patties added with EP had lower TBARS values than control during storage. Volatile basic nitrogen (VBN, mg%) contents of all patties also increased during storage time with O2 and F2 having lower values than control. Therefore, EP might have potential as a natural antioxidant in meat products during storage.

Effects of exogenous AHLs on the spoilage characteristics of Pseudomonas koreensis PS1.

Some specific spoilage organisms (SSO) respond to the presence of exogenous N-acyl-homoserine lactones (AHLs) through the quorum sensing (QS) system to modulate their spoilage characteristics. To explore the effect of exogenous AHLs on the spoilage characteristics of Pseudomonas koreensis PS1 from spoiled chilled pork, four kinds of AHLs were added to the liquid medium to analyze their effect on the cell growth and spoilage characteristics of P. koreensis PS1, and N-hexanoyl-l-homoserine lactone (C6-HSL) was added to evaluate its effect on spoilage characteristics of P. koreensis PS1 inoculated in fresh chilled pork. The results showed that the addition of low concentrations of C6-HSL (10µmol/L) to the liquid medium could remarkably promote the protease activity, lipase activity, and biofilm formation of P. koreensis PS1 (p < 0.05), and more than 30µmol/L C6-HSL could significantly increase the cell density (p < 0.05). Furthermore, the addition of 10µmol/L C6-HSL into fresh chilled pork could increase the lipase and protease activities of P. koreensis PS1. The enzyme activity accelerated the decomposition of total protein, total fat, and total sugar, and led to an increase in putrescine, tyramine, cadaverine, and total volatile basic nitrogen (TVB-N) content in chilled pork during the storage at 4°C. PRACTICAL APPLICATION: The infestation of chilled pork with SSO may be a challenge for the meat industry. In this study, exogenous AHLs were found to have a positive effect on the spoilage of chilled pork. The elimination of the QS phenomenon of bacteria should be considered when looking for ways to prolong the preservation of chilled pork.

Effect of gelatin-based active coatings formulated with rosemary extract on quality of cold stored meatballs

Meatballs were coated by gelatin-based mixes incorporated with potassium sorbate and rosemary extract. Coated samples were evaluated by free fatty acids (FFAs), thiobarbituric acid reactive substances (TBARS), and total volatile basic nitrogen (TVB-N) content. In addition, texture profile analysis (TPA) was performed to evaluate the textural features of meatballs. Uncoated sample as control along with 3 other samples coated by different formulations were stored in zipped plastic bags at +4 °C for 10 days. No significant difference was observed between samples regarding FFA and TBARS although coating with potassium sorbate showed suppressive effect on TVB-N initially. The starting pH of meatball was 6.22 and the coatings generally limited the change in pH compared to the control. Although significant differences in color were observed due to the color of coating itself, the coatings limited the variations in color to some extent. Other quality parameters were not improved much with the studied formulations. It is concluded that active edible coatings might be utilized in muscle foods for preservation and shelf-life extension if appropriately formulated and applied. Comprehensive studies are needed to determine the performance of carrier polymers in release of active ingredients and suitable formulations for every single group of food.

Quality of reduced sodium shrimp paste from shrimp head as alternative source

The significantly decreased availability of the main raw materials for making shrimp paste is a big problem, while most by-products from shrimp processing, especially head, are not yet properly used. Therefore, using shrimp head for shrimp paste production is well motivated. However, traditional shrimp paste is high in salt and can impact health via hypertension, kidney, or cardiovascular disease. This study aimed to produce a reduced sodium shrimp head paste, using 12, 14 or 16-fold amount of shrimp heads relative to salt. The salted shrimp head was fermented for 14-16 hr. Thereafter, it was dried at 60 °C, then ground and fermented further for 30 d. The paste was dried again to 40-45% moisture content and fermented for another 90 d. The total viable count and lactic acid bacteria significantly decreased in all treatments, and no pathogenic microorganisms were detected. After fermentation for 90 d, the aw had decreased in all treatments. The highest shrimp head proportion (16:1) exhibited the highest total volatile basic nitrogen (TVB-N) and trimethylamine (TMA) contents. In conclusion, shrimp head can serve as an alternative raw material in shrimp paste with comparatively low salt content that may reduce the risks of hypertension, cardiovascular disease, and stroke.