Optimization of Foaming Parameters and Investigating the Effects of Drying Temperature on the Foam-Mat Drying of Shrimp (Penaeus indicus)

In this study, foaming conditions of shrimp (Penaeus indicus) were optimized using response surface methodology (RSM) and the effect of drying temperature on drying behavior was investigated. The experiments were conducted according to face-centered central composite design for three independent variables: xanthan gum concentration (0.1–0.4% w/w), whipping time (2–6 min), and water : shrimp ratio (2:1–6:1 w/w) to minimize the foam density (FD) and the drainage volume (DV) as responses. Statistical analysis of results showed that linear terms of the models were significant (p < 0.01) except the linear term of whipping time in DV. Xanthan gum concentration 0.19% (w/w), water : shrimp ratio 4.5:1 (w/w), and whipping time 5.89 min were found to be the optimum foaming conditions. The effect of different drying temperatures (45, 60, 75, and 90°C) on drying behavior of optimized foam was then evaluated. The drying air temperature had a considerable effect on drying time and drying rate. As the temperature increased from 45 to 90°C, the drying time decreased to 90 min. Drying rate curves showed that foam-mat drying of shrimp principally occurred in the constant rate period. Different mathematical models were tested with the drying behavior of shrimp foam in the dryer. According to the results, the Weibull distribution model is superior to the other models for explaining the drying behavior. Effective moisture diffusivity was calculated and was between 1.114 × 10^?8 and 3.951 × 10^?8 m²/s within the studied temperature range. An Arrhenius relation with an activation energy value of 26.89 kJ/mol expressed the effect of temperature on diffusivity.     

Fortification of Skim Milk with Nanoliposomes Loaded with Shrimp Oil: Properties and Storage Stability

Shrimp oil nanoliposomes (SONL) were fortified into skim milk at various levels (2–10%, v/v), followed by pasteurization at 63 °C for 30 min. Skim milk showed lowered whiteness but increased redness and yellowness as SONL levels added increased (P < 0.05). Viscosity of fortified samples was also augmented with increasing levels of SONL (P < 0.05). Sensory analysis indicated that fortified milk skim samples had no perceivable fishy odor and were organoleptically acceptable. When skim milk fortified with 10% SONL was stored up to 15 days at 4 °C, the microbial load was less than 2.54 log CFU mL⁻¹. The pH and acidity values were also within the acceptable limits. As measured by peroxide value (PV) and thiobarbituric acid reactive substances (TBARS), shrimp oil in SONL did not undergo oxidation during the extended storage. The fatty acid profile of shrimp oil revealed no loss of polyunsaturated fatty acids taken place during the storage of fortified milk. Therefore, nanoliposomes could be an effective carrier for shrimp oil to be fortified in skim milk.     

Antibacterial activity of chitin,chitosan and its oligomers prepared from shrimp shell waste

The antimicrobial activities of chito-oligosaccharides against four Gram-positive and seven Gram-negative bacteria were compared to chitosan and chitin with an emphasis on the effects of biopolymer molecular weight (Mv) and degree of deacetylation (DD). Chitin was isolated from shrimp (Parapenaeus longirostris) shell waste by sequential chemical treatments. Chitosan and its oligomers N-acetyl chito-oligosaccharides and chito-oligosaccharides were prepared by deacetylation and chemical hydrolysis, respectively. Chitin exhibited a bacteriostatic effect on Gram-negative bacteria, Escherichia coli ATCC 25922, Vibrio cholerae, Shigella dysenteriae, and Bacteroides fragilis. Chitosan exhibited a bacteriostatic effect on all bacteria tested, except Salmonella typhimurium. The oligomers exhibited a bactericidal effect on all bacteria tested.     

Identification of hemocyanin as a novel non-cross-reactive allergen from the giant freshwater shrimp Macrobrachium rosenbergii

Scope : Sensitization to giant freshwater shrimp Macrobrachium rosenbergii (Mr) was recently reported. However, the allergens have yet to be identified. This study aimed to identify and characterize a novel allergen of Mr shrimp. Methods and results: Extracted proteins were separated and purified by anion and in some experiments, size‐exclusion chromatography. Serum IgE from shrimp allergic donors identified a candidate protein, which was characterized by LC‐MS/MS. The specificity of IgE binding was tested using immunoblotting and inhibition ELISA. The IgE‐binding profiles from 12 of 13 Mr allergic subjects that were pre‐incubated with an extract of Penaeus monodon showed residual binding to ～60–80 kDa proteins. The 60–80 kDa IgE‐bound proteins were fractionated in the flow‐through of anion chromatography showing a high IgE reactivity. Peptides identified by LC‐MS/MS showed the proteins closely match subunits of hemocyanin (Hcs). Purified Hcs from hemolymph markedly inhibited binding of IgE from sera of Mr allergic subjects to solid‐phased Mr proteins in inhibition ELISA. Conclusion: Hcs were identified as heat‐stable, non‐cross‐reactive, high‐molecular‐weight (MW) allergens from Mr shrimp. Since circulatory organs are not always removed during food preparation, high concentrations of Hcs may be present along with shrimp meat, which contains the known cross‐reactive tropomyosin protein.     

2013~2015年湖北地区虾中硝基呋喃代谢物残留的监测分析

目的 分析湖北省2013年～2015年347份虾产品中硝基呋喃类药物的残留情况,以期为硝基呋喃代谢物的来源和危害分析提供科学依据。方法 采用超高效液相色谱串联质谱法（UPLC-MS/MS）检测湖北9个地区多种虾产品中四种硝基呋喃类代谢物残留量,并用Excel 和SPSS16.0对实验数据进行统计学分析。结果 硝基呋喃类药物的代谢产物的总体检出率为27.09%,检出的代谢物均为氨基脲（SEM）,河虾的检出率最高,为61.54%,其次是基围虾为6.78%;最低是小龙虾为1.38%;对于整体匀浆的带壳河虾样品,检出率高达91.67%,而去壳的河虾虾肉样品没有检出SEM。结论 湖北地区的虾产品中存在不同程度的硝基呋喃污染情况,同时,发现河虾中有内源性的SEM的存在。结合湖北地区居民的膳食消费结果,进行虾中SEM的风险评估,发现虾中SEM暴露对人类健康危害较小。     

Trihalomethanes formation potential of shrimp farm effluents

Shrimp farm effluents along the Bangpakong River in the Chachoengsao Province of Thailand were evaluated for their trihalomethane formation potential (THMFP) and related parameters. The dissolved organic carbon (DOC), salinity and bromide ion concentrations of shrimp farm effluents were in the ranges of 12-14 mg/L, 0.1-14.5 ppt, and 0-14 mg/L, respectively. The dissolved organic matter was fractionated into hydrophobic and hydrophilic fractions having a range concentration of 3-5 and 8-10mg/L, respectively. The THMFP for all shrimp farm effluents analyzed was in the range of 810-3100 microg/L. The hydrophilic organic fraction was found to be a more active precursor of trihalomethanes (THMs) with 700-966 microg/L THMFP obtained from this fraction, while only 111-363 microg/L THMFP was derived from the hydrophobic fraction. The experimental results showed that salinity and bromide played crucial roles in the formation of THMs. At low salinity and bromide levels, chloroform was the dominant THM species, whereas at high salinity and bromide levels, bromoform became the dominant species. A Fourier Transform Infrared (FTIR) spectrum analysis of the samples before and after chlorination illustrated that the functional groups involved in the THM formation reaction were phenolic compounds, amines, aromatic hydrocarbons, aliphatic bromo-compounds, and aliphatic chloro-compounds.     

冷冻海鲜虾饼加工技术

本文介绍了冷冻海鲜虾饼的加工技术,并重点总结了冷冻海鲜虾饼生产过程中的温度管理和技术操作要点。     

2019年河北省市售虾蛄(皮皮虾)重金属污染情况调查

目的 了解2019年河北省市售虾蛄中重金属污染情况.方法 按照《2019年河北省食品污染物风险监测方案》的要求,对河北省11个地市及雄安新区共计106份虾蛄样品进行Pb、Ni、Hg(总)、As(总)、Li、V、Mn、Ba、Cd、Cr、Al、Sb、Cu、Sn、Se共15种元素的检测,并对检测结果进行统计分析.结果 Hg、...     

Chemical and biological characteristics of protein hydrolysates from fermented shrimp by-products

Protein hydrolysates were prepared through lactic acid fermentation of the inedible portions of shrimp (cephalothorax and exoskeleton), the by-products of shrimp processing operations. The protein-rich liquid hydrolysate was further processed into a concentrated paste via vacuum evaporation at 80 °C or was also processed into a dry powder using a spray drying method at 180 °C/140 °C (inlet/outlet temp). The laboratory compared the composition of the three forms of shrimp protein hydrolysates. The protein and ash content of the hydrolysates ranged from 8.43 ± 0.22 to 46.73 ± 1.29 and 2.03 ± 0.52 to 8.25 ± 0.14 g/100 g of wet weight. All the samples were analyzed for fifteen amino acids; the powder form was analyzed for colour, microbial content, and for heavy metal occurrence. The shrimp by-products were successfully converted into micro-nutrient by-products rich in amino acids for potential recommendations in the supplementation of animal and human diets.     

Characterisation of trypsin purified from the viscera of Tunisian barbel (Barbus callensis) and its application for recovery of carotenoproteins from shrimp wastes

Trypsin was purified from the viscera of barbel by precipitation using ammonium sulphate (0-80%), Sephadex G-100, and Mono Q-Sepharose ion exchange chromatography. The trypsin was purified 27-fold, with 79 U/mg specific activity and 31% recovery. The enzyme had a molecular weight of 24 kDa; purified trypsin appeared as a single band on native-PAGE. The optimum pH and temperature for enzyme activity were pH 10.0 and 55 °C with BAPNA used as a substrate. The N-terminal amino acid sequence of the first 12 amino acids of the purified trypsin was IVGGYECTPYSQ. The Michaelis-Menten constant (K_m) and catalytic constant (k_cat) values of the enzyme were 0.018 mM and 1.21 s⁻¹, respectively. The study also investigated the effects of purified trypsin on the recovery of carotenoproteins from shrimp (Parapenaeus longirostris) shells through hydrolysis using 1.0 U barbel trypsin/g shrimp shells for 1 h at 30 °C. The freeze-dried carotenoproteins recovered contained 71.09% protein, 16.47% lipid, 7.78% ash, and 1.79% chitin.