Comparative evaluation on shelf life extension of MAP packed Litopenaeus vannamei shrimp treated with natural extracts

Insight into the correlation of key taste substances and key volatile substances from shrimp heads at different temperatures

This study aimed to investigate taste substances of shrimp heads stored at 20 °C, 4 °C, -3 °C, and - 18 °C, and the correlation between taste substances and 25 key volatile substances. Notably, samples stored at 20 °C showed significant changes in bitter amino acids and hypoxanthine, and quickly deteriorated. Samples stored at 4 °C for 14 d or - 3 °C for 30 d facilitated the development of umami amino acids, sweet amino acids, and IMP. Furthermore, samples stored at -18 °C for 30 d demonstrated no significant changes in taste profile. Changes in taste substances through quantitative analysis were consistent with changes in taste profile through e-tongue analysis. Based on the results of O2PLS (VIP > 1), Cys, Arg, Glu, Ser, Val, Ala, Ile, ADP, and IMP were correlated with 25 key volatile substances. This study provides fundamental data for the storage, transportation, and value-added utilization of shrimp heads.

PvMR1, a novel C-type lectin plays a crucial role in the antibacterial immune response of Pacific white shrimp, Penaeus vannamei

C-type lectins (CTLs) are important immune molecules in innate immune, which participate in non-self recognition and clearance of pathogens. Here, a new CTL with two distinct C-type lectin domains (CTLDs) from Pacific white shrimp Penaeus vannamei, designated as PvMR1 was identified. The obtained PvMR1 coding sequence (CDS) was 1044 bp long encoding a protein with 347 amino acids. PvMR1 had two CTLD, a conserved mannose-specific EPN motif and a galactose-specific QPD motif, clustering into the same branch as the crustacean CTLs. PvMR1 was widely distributed in shrimp tissues with the highest transcription level in the hepatopancreas, with significantly induced mRNA expression on the hepatopancreas and intestines after immune challenge with Vibrio anguillarum. In vitro assays with recombinant PvMR1 (rPvMR1) protein revealed that it exhibited a wide range of antimicrobial activity, bacterial binding ability, and bacterial agglutination activity in a Ca2+-independent manner. Moreover, PvMR1 promoted bacterial phagocytosis in hemocytes. Furthermore, rPvMR1 treatment could significantly enhance the bacterial clearance in hemolymph and greatly improved the survival of shrimp under V. anguillarum infection in vivo. These results collectively suggest that PvMR1 plays an important role in antibacterial immune response of P. vannamei.

Optimization of ultrasonic-assisted extraction of flavor compounds from shrimp by-products and characterization of flavor profile of the extract

This study aimed to optimize the ultrasonic-assisted extraction conditions of flavor compounds from white shrimp heads (WSHs). The effects of sonication amplitude, sonication time, and solvent-to-solid ratio on the extraction yield (EY) of flavor compounds and the degree of protein modification (DPM) were evaluated by Box-Behnken design and response surface methodology (RSM). The optimum EY (40.87 %) and DPM (26.28 %) were obtained at amplitude, time, and solvent-to-solid ratios of 63.2 %, 20.5 min, and 20.8 mL/g, respectively. The optimum DPM value indicates that sonication markedly influenced the protein denaturation, as evidenced by the higher TCA soluble protein content. Further, we also investigated the taste active composition of ultrasonic extract of shrimp head (USH). Results show that the equivalent umami concentration (EUC) value was significantly (p < 0.05) increased in the ultrasonic extract of shrimp head (USH) (55.44 ± 3.25 g MSG/100 g) compared to the control shrimp head extract (CSH) (8.32 ± 1.07 g MSG/100 g). This study also deals with the development of shrimp flavor concentrate (SFC) using USH by the conventional heating process. Sensory evaluation of SFC revealed that the shrimp-like aroma and umami taste characteristics were predominant. Thus, USH's improved umami taste composition demonstrates its potential utilization for producing SFC with higher EUC.

Efficacy of Chitosan Oligosaccharide Combined with Cold Atmospheric Plasma for Controlling Quality Deterioration and Spoilage Bacterial Growth of Chilled Pacific White Shrimp (Litopenaeus vannamei)

A novel food processing technique based on the combination of cold atmospheric plasma (CAP) and chitosan oligosaccharide treatment (COS) was developed to enhance antibacterial performance and extend the shelf life of Pacific white shrimp (Litopenaeus vannamei). Effects of different treatments on the microbial community composition, physicochemical properties, and post-storage behaviors of Pacific white shrimp were evaluated during chilled storage for up to 10 days. Results showed that the synergistic effects of COS and CAP could be obtained, largely inhibiting the growth of microorganisms. The content of total volatile basic nitrogen (TVB-N), total viable counts (TVC), and pH value in treated groups were lower than in the control group and the loss of moisture content, water activity, and sensory score were observed. Compared to the control group, shrimp was on the verge of spoilage on the 6th day of storage, while the COS-CAP-treated shrimp had a 4-day lag period. Moreover, the COS and CAP could effectively inhibit the growth of Aliivibrio, the predominant microbial group in the ultimate storage period. This study suggests that the combined utilization of COS and CAP could be a high-efficacy technique for extending the shelf-life of shrimp.

The Therapeutic Alliance between Pomegranate and Health Emphasizing on Anticancer Properties

Pomegranate is a fruit bearing-plant that is well known for its medicinal properties. Pomegranate is a good source of phenolic acids, tannins, and flavonoids. Pomegranate juice and by-products have attracted the scientific interest due to their potential health benefits. Currently, the medical community has showed great interest in exploiting pomegranate potential as a protective agent against several human diseases including cancer. This is demonstrated by the fact that there are more than 800 reports in the literature reporting pomegranate's anticancer properties. This review is an update on the research outcomes of pomegranate's potential against different types of human diseases, emphasizing on cancer. In addition, perspectives of potential applications of pomegranate, as a natural additive aiming to improve the quality of animal products, are discussed.

Differentiation of Penaeus vannamei from different thermal processing methods in physico-chemical, flavor and sensory characteristics

Differentiation in physico-chemical, flavor and sensory characteristics of shrimps (Penaeus vannamei) after direct roasting (DR, 200 °C), boiling (100 °C/2 min) + roasting (BR), steaming (100 °C/2 min) + roasting (SR) and microwaving (280 W/2 min) + roasting (MR) was investigated. BR, SR, and MR endowed shrimps with better texture to varying degrees and significantly (P < 0.05) increased lightness when compared to DR, which closely related to their different water status. High correlations between nuclear magnetic resonance data and quality properties were found by partial-least-squares regression (PLSR). Shrimps possessed by SR significantly (P < 0.05) increased the proportion of sweet amino acids (63.89 ± 0.92%), with superior umami and richness detected by electronic tongue. Compared with DR, both SR and MR endowed shrimps with richer ester, while BR endowed shrimps with richer hydrocarbons. Roasting combined with other thermal processing would favor improving the quality of shrimp products.

Quality improvement of shrimp ( Litopenaeus vannamei ) during refrigerated storage by application of Maillard peptides/water‐soluble chitosan coating

We investigated the effect of squid Maillard peptides (SMPs) on the shelf life and quality of shrimp for 20 days. Water‐soluble chitosan coatings incorporated with SMPs (SMPs + chitosan) were applied to shrimp under chilled conditions. Untreated samples were used as control, along with samples treated with water‐soluble chitosan and SMPs alone. The pH increase was observed in all samples, as well as increased total plate count, total volatile basic nitrogen, peroxide value, and thiobarbituric acid index. However, these indexes in the SMPs + chitosan group were lower than the other three groups, which suggested SMPs + chitosan might play a role in retarding quality loss of shrimp, and there might be a combined effect between water‐soluble chitosan and SMPs. Based on hardness, springiness, and sensory evaluation, shrimp coated with SMPs + chitosan was the best preserved, with a shelf life of 16 days but only 8–12 days for other samples. The present work demonstrates the effectiveness of SMPs + chitosan, offering a promising alternative to inhibit microbial growth and lipid oxidation on shrimps during refrigerated storage.

Significantly Different Lipid Profile Analysis of Litopenaeus vannamei under Low-Temperature Storage by UPLC-Q-Exactive Orbitrap/MS

Low-temperature storage is one of the most important preservation methods for aquatic product storage. However, the effects of low-temperature storage on the lipid profiles of shrimp are unclear. Herein, UPLC-Q-Exactive Orbitrap/MS combined with LipidSearch software was applied to analyze the effect of three low storage temperatures (4 °C, -2 °C, and -18 °C) on the lipidomics of Litopenaeus vannamei. A total of 15 lipid classes were analyzed, and PC, PE, DG, and TG accounted for vast majority of peak areas. Furthermore, 531 individual lipid variables enriched in 12 metabolic pathways were identified via bioinformatics analysis methods. A total of 56 significantly different lipid molecular species (55 belonging to PC, PE, DG, and TG) were selected as potential biomarkers of lipid oxidation via correlational analysis between physical properties (texture and color) and individual lipid variables. The results indicated that the three low storage temperatures caused different effects on the lipidomics profile of L. vannamei, and PC, PE, DG, and TG could become potential focuses in further studies of lipid oxidation in L. vannamei.

Combined Effect of High-Pressure Processing with Spice Extracts on Quality of Low-Salt Sausage during Refrigerated Storage

The study evaluated the combined effect of high-pressure processing (HPP) and spice extracts on low-salt sausages during refrigerated storage. Physicochemical and microbiological characteristics of the sausages were determined. HPP treatment increased the thiobarbituric acid reactive substances (TBARS) value and the carbonyl content of the samples (p < 0.05), which meant lipid and protein oxidation was accelerated. Adding clove and cinnamon extracts can retard the oxidation caused by HPP (p < 0.05). The pH of the sausages treated with both the spice extracts and HPP maintained a higher pH value during the storage (p > 0.05). Compared with the samples treated with HPP or with the spice extracts alone, the combined treatment observably inhibited the growth of spoilage bacteria (p < 0.05) and improved the microbial community. The results demonstrated that the use of clove and cinnamon extracts in conjunction with HPP improved the storage quality and prolonged the shelf-life of the low-salt sausages. Thus, the combined use of spice extracts and HPP can be developed as a promising way to preserve low-salt meat products.

Models for Predicting Quality of Solar-Dried Shrimp (Penaeus vannamei) during Storage Based on Protein Oxidation

The purpose of this study was to explore the correlation between protein oxidation and quality and to study the changes in various indexes of solar-dried shrimp (Penaeus vannamei) stored at 37°C and 20°C through vacuum packing and vacuum packaging with antipressure sterilization. The results showed that ΔE as well as TVB-N and carbonyl contents increased, whereas moisture and free thiol (SH) contents decreased with time. Furthermore, SDS-PAGE and scanning electron microscopy revealed protein degradation and damage of shrimp muscle microstructure during storage. A quality prediction model based on protein oxidation was established according to Arrhenius equation. Verification of shrimp quality prediction models revealed that the relative errors of the models based on SH and carbonyl contents were below 10%, indicating that these protein oxidation parameters can be used for reliable estimation of quality changes in dried shrimp during storage.

Ultrasound-assisted extraction of guava and papaya leaves for the development of functional shrimp patties

The current study was aimed to evaluate the effects of guava and papaya leaves extract on the antioxidant profile and their outcomes in the storage stability of shrimp patties. Total of seven treatments were prepared by employing guava leaf extract (GLE) and papaya leaf extract (PLE) including control. Both the extracts were employed in the concentration of 1% and 2% each and in combination as 1:1% and 2:2%, respectively. The shrimp patties were kept in ziplock bags at refrigeration temperature, and further analysis was done after 21 days of storage period with intermittent evaluation interval of 7 days. The antioxidant capability of functional shrimp patties was determined by total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP). Higher significant values of TPC, DPPH, and FRAP were observed in the functional shrimp patties enriched with GLE2%:PLE2% at start of the experiment. The physicochemical parameters were observed by hunter color, TVBN, TBARS, and peroxide value (POV). Higher significant values of TVBN, TBARS, and peroxide were observed in the control samples as compared to treatment group GLE2%:PLE2%. The bacterial counts were also higher in control samples as compared to the treatment group GLE2%:PLE2%. The sensorial attributes were observed regarding appearance, taste, texture, odor, and overall acceptability. The maximum scores related all parameters were gathered by control group but significantly lower scores were for the group GLE2%:PLE2%. In conclusion, functional shrimp patties enriched with GLE2%:PLE2% showed better antioxidant capacity, stability, and sensory characteristics during storage.

Chemical Biopreservative Effects of Red Seaweed on the Shelf Life of Black Tiger Shrimp (Penaeus monodon)

Hypnea musciformis (HM) and Acanthophora muscoides (AM) red seaweeds were evaluated for their antioxidant properties and efficacy to extend the chemical shelf life of black tiger shrimp (Penaeus monodon) during 14-daystorage. Treated shrimp were soaked in five percent ethanolic solution with 500 µg/mL of AM or HM powder for 30 min. HM had more phenols and flavonoids, increased radical scavenging activity, and greater H₂O₂ reducing power than AM in vitro. Biochemical quality indicators were significantly higher in the control group, followed by HM- and AM-treated samples during storage. On day 14 of storage, controls contained significantly higher amounts of biogenic amines than HM- or AM-treated samples. The shelf life of chilled stored shrimp increased due to the presence of compounds of butylated hydroxytoluene, sulfurous acid, heptadecane, mono (2-ethylhexyl), and 1,2-propanediol found in AM extract and sulfurous acid and 1,2-propanediol found in HM extract. A control group was soaked in the same ethanolic solution as treated samples without algae powder for 30 min. Each group was kept ice-cold during the soaking period. The results obtained demonstrate the usefulness of two seaweed extracts, Hypnea musciformis and Acanthophora muscoides, combined with ice by decreasing the formation of toxic biogenic amines in shrimp, enhancing its shelf life during ice storage.

Impact of different drying processes on the lipid deterioration and color characteristics of Penaeus vannamei

BACKGROUND

Fresh shrimp (Penaeus vannamei) deteriorates easily and the drying process is an important processing method for prolonging the shelf life of shrimp. The traditional drying method is hot-air-drying (HD), which can cause some problems such as nutrient loss, discoloration and lipid oxidation. In recent years, freeze-drying (FD) has been popular for removing moisture from food at lower temperatures, maintaining the structure of raw materials, and improving storage stability of products. In the present study, the effects of HD and FD on lipid and color of P. vannamei and the mechanisms involved were investigated.

RESULTS

FD caused less lipid oxidation compared to HD; consequently, FD-processed shrimps had lower levels of primary and secondary oxidation products, as well as acid value, and higher contents of triacylglycerol, phosphatidylcholine, phosphatidylethanolamine, eicosapentaenoic acid and docosahexaenoic acid compared to HD-processed samples. Lipase and lipoxygenase played a role in the oxidation and hydrolysis of lipids during drying process. FD-processed shrimps had lower yellowness value and chromatic aberrations but a higher whiteness value compared to HD-processed samples. Correlation analysis showed that lipid oxidation, astaxanthin degradation and the Maillard reaction contributed to the changes of color. Principal component analysis indicated that FD caused less deterioration in quality compared to HD.

CONCLUSION

In the present study, FD is recommended for preserving shrimp color and lipid nutrition in terms of lipid oxidation control. © 2020 Society of Chemical Industry.

Pomegranate peel as phenolic compounds source: Advanced analytical strategies and practical use in meat products

The growing demand for natural food preservatives has promoted investigations on their application for preserving perishable foods. Consequently, the meat market is demanding natural antioxidants, free of synthetic additives and able to diminish the oxidation processes in high-fat meat and meat products. In this context, the present review discuss the development of healthier and shelf stable meat products by the successful use of pomegranate peel extracts containing phenolics as natural preservative agent in meat and meat products. This paper carries out an exhaustive review of the scientific literature on the main active phenolic compounds of pomegranate peel identified and quantified by advances in the separation sciences and spectrometry, and its biological activities evaluation. Moreover, the impact of pomegranate peel use on the quality and oxidative stability of meat products is also evaluated. As natural preservative, pomegranate peel phenolics could improve stored meat products quality, namely instrumental color retaining, limitaion of microflora growth, retardation of lipid and protein oxidation.