Sensory Quality and Shelf Life of MAP Redfish (Sebastes marinus) Fillets as Affected by Previous MA Bulk Storage of Whole Fish

Abstract

The shelf life of iced redfish is known to be 16–19 days. This study evaluated the effects of modified atmosphere (CO₂/N₂: 60/40) in bulk storage of redfish and subsequent modified atmosphere packaging (MAP) of fillets. Fish were evaluated by sensory, microbiological and chemical methods. Modified atmosphere (MA) bulk storage of whole fish for more than 5 to 10 days did not improve their sensory quality or significantly increase shelf life. In fact, the study showed negative effects in texture and overall appearance. MAP of fillets processed from 10-day MA bulk stored fish showed a modest increase in shelf life, but negatively affected their texture. Sensory qualities, i.e., tenderness, that decreased under MA bulk storage were improved upon aerobic storage for fish stored under MA for 5 to 10 days, but not 14 days. Lower microbial levels were found in MA bulk stored fish and MAP fillets compared to traditionally iced fish, while higher TMA levels were found in MAP fillets.     

Effect of Customized Probiotics on the Physiological and Immunological Responses of Juvenile Western King Prawns (Penaeus latisulcatus Kishinouye, 1896) Challenged with Vibrio harveyi

Juvenile western king prawn P. latisulcatus were fed 10⁵ colony-forming units (CFU)/mL of two probiotics Pseudomonas synxantha and P. aeruginosa for 28 days. P. latisulcatus were then challenged with V. harveyi at 0 (control), 10³, 10⁵, and 10⁷ CFU/mL. During the seven days of challenge, disease resistance of the probiotic-fed prawns was compared with that of prawns not fed probiotics. The immunological responses of the prawns did not improve during the challenge period in terms of total haemocyte count, hyalinocyte, semi-ganulocyte, granulocyte, clotting time, bacteraemia, and intestinal bacterial load. Overall, when prawns were challenged with V. harveyi, the LT₅₀ values got shorter as V. harveyi concentration increased. LT₅₀ values of prawns fed probiotics were significantly longer (P < 0.05) than those not fed probiotics. At a V. harveyi concentration of 10³ CFU/mL, the 100% survival of the prawns fed probiotics was three times more likely than those of the prawns not fed probiotics.     

Global scale of freshwater prawn farming

In welcoming participants to Giant Prawn 2011, the authors briefly review the current scale of this component of global aquaculture. The expansion of freshwater prawn farming over the 30 years since the first global conference on this topic [Giant Prawn 1980 (GP1980)] is examined. At the time of GP1980, the output of farmed giant river prawns (Macrobrachium rosenbergii) was <3000 t. Almost three decades later (2009) the total annual aquaculture production of all species of freshwater prawns had risen to almost 444 000 t, with a value of US$2.2 billion. The farmed production of M. rosenbergii constituted 51.7% of the global total, while the oriental river prawn M. nipponense (reared totally in China) contributed 47.2%. The contribution of the monsoon river prawn M. malcolmsonii remains quite small so far, and does not show in the above percentages because no recent FAO data are available for this species. In 2007, however, the latter species contributed 1.0% of the total global production of freshwater prawns. The major freshwater prawn producing countries are in Asia (e.g. Bangladesh, China, India, Myanmar, Taiwan, Thailand and Vietnam) but Macrobrachium spp. are also farmed in other continents.     

A review on the diseases of freshwater prawns with special focus on white tail disease of Macrobrachium rosenbergii

Freshwater prawns, particularly, the Giant Freshwater prawn Macrobrachium rosenbergii, are one of the most economically important farmed species in the world. Faced with increasing disease problems in penaeid shrimp culture, farmers turned to freshwater prawn farming. Freshwater prawns were considered relatively less susceptible to diseases. However, with intensification of culture and increased world trade of the farmed species, emerging diseases are beginning to constitute an increasingly serious health problem in freshwater prawn culture. This article is a review of the important diseases reported in freshwater prawns, with particular emphasis on the white tail disease of M. rosenbergii as it is the most important disease recorded to date and also the most well studied among the diseases of freshwater prawns. Steps to be taken for proper health management in the farming of this species is also touched upon.     

The case for all‐female freshwater prawn,Macrobrachium rosenbergii (De Man), culture

The prevailing notion in the prawn (Macrobrachium rosenbergii) culture industry is that the large male prawns that dominate the product value in research and commercial populations should, alone, be the target of commercial mono‐sex (all‐male) culture. However, studies have shown that the male prawn's response to increasing density (intensification) is controlled by a strong hierarchical dominance‐based social structure resulting in a large, disproportionate, increase in low value small animals in the ‘lower’ modal class of the male prawn size distribution. In contrast, prawn females and other aquatics, such as marine shrimp, display a moderate and uniform response to intensification in all size classes. Indeed, the densities in which prawn male superiority has been demonstrated are well below those used in intensive marine shrimp culture. This article: (1) discusses the background to the issue, (2) discusses the notion that because female prawns appear to be ‘marine shrimp‐like’ – with a normal size distribution indicating a lack of a strong social dominance – this will render them superior to all‐males under intensive growing conditions, (3) presents a ‘rate‐of‐response‐to‐density’ model projecting a female‐superior response to high previously untested densities, (4) summarizes results of a pond field test conducted at Auburn University (Auburn, AL, USA) to test the model's results whereby hand‐sexed prawns in treatment‐replicated in‐pond cages at densities of 10, 25, 40 and 55/m² showed that all‐female prawns give higher production and product value than males under intensive conditions, (5) discusses the use of biotechnological methods to sex‐reverse brood‐stock to produce all‐females and (6) discusses the notion that the potential of genetic selection to increase prawn production is only possible using females.     

Efficacy of fermented prawn shell waste as a feed ingredient for Indian white prawn, Fenneropenaeus indicus

Prawn shell waste collected from shrimp‐processing plants in Cochin, India, was subjected to fermentation using 20 chitinoclastic and proteolytic/non‐proteolytic bacterial strains. The products generated were analysed for protein, lipid, total sugars, N‐acetyl glucosamine, free amino acids and ash. Shrimp diets were prepared using these 20 fermented products and a control diet using raw prawn shell waste. Feeding experiment was conducted with postlarvae (PL21) of Indian white prawn, Fenneropenaeus indicus for a period of 21 days. Biogrowth parameters such as mean weight gain, feed conversion ratio, specific growth rate and protein efficiency ratio were estimated and the animals were challenged with white spot virus orally via diet. Enhanced growth could be observed in prawns fed F134 and F124, incorporated with the fermentation products generated using Bacillus spp., C134 and C124 respectively. The percentage survival of prawns after 7 days of challenge was found to be highest for groups fed diet F111 incorporated with fermentation product generated using Bacillus sp. These products of bacterial fermentation hold promise as growth enhancers and immunostimulants in aquaculture.     

杂交青虾“太湖1号”苗种在池塘养殖中的适宜放养密度

以饲料系数、养殖产量、成虾规格、体长与体质量特定生长率作为判据,水质状况作为参考,以杂交青虾"太湖1号"为实验对象,在放养密度为60、105、150、195、240尾/m35个梯度下进行为期100 d的养殖试验,研究杂交青虾"太湖1号"苗种在池塘养殖中的适宜放养密度。结果显示,150尾/m3组的饲料系数显著低于195尾/m3和240尾/m3组(P<0.05),而养殖产量及成虾规格显著高于其它各组(P<0.05)。在高于150尾/m3的高密度组中,虽然产量也显著高于低密度组(P<0.05),但成虾规格较小。养殖期间各养殖水体的水质均能满足养殖虾的生长需求;高温季节除了高密度组的亚硝态氮盐指标稍有升高以外,水体pH、DO、NH4+-N等指标基本保持一致。将放养密度分别与饲料系数、增重率、体长与体质量特定生长率等指标之间进行二次回归曲线方程拟合,计算出杂交青虾"太湖1号"的适宜放养密度为117～150尾/m3。     

SOCIOECONOMIC ASPECTS OF SMALL-SCALE FRESHWATER PRAWN MARKETING SYSTEMS IN MYMENSINGH,BANGLADESH

An investigation was carried out in Mymensingh region of Bangladesh to understand current practices of freshwater prawn (Macrobrachium rosenbergii) marketing systems. Prawn marketing is almost exclusively maintained by the private sector, where the livelihoods of a considerable number of people are associated with prawn distribution and marketing systems. The market chain from producers to consumers passes through a number of intermediaries. The prawn is a highly valued product in international markets; most of the prawns (60%) are therefore exported, particularly to the USA, Japan and Europe. The rest (40%) of the under-sized prawns are sold to local markets in Mymensingh. The price of prawn depends on quality, size and weight, and grade. In spite of marketing constraints, livelihood outcomes are positive and most of the households of traders (75%) have improved their social and economic conditions through prawn marketing activities. However, concerns arise about the long-term sustainability of prawn marketing due to poor road and transport facilities, inadequate supply of ice, lack of money and credit facilities, and poor market infrastructure. It is therefore necessary to provide institutional, organizational, and government support for a sustainable prawn market.     

Preservation of Stuffed Mussels at 4°C in Modified Atmosphere Packaging

The stuffed mussel is a traditional, ready-to-eat food in Turkey which is produced by cooking rice and various spices filled inside the mussel. This article examines the effect on sensory, chemical, and microbiological parameters of stuffed mussels of two gas mixtures—MAP1 50% N₂/50% CO₂ and MAP2 100% CO₂—used as modified atmospheres for cold storage at +4°C. Air packaged samples were chosen as the control group. Based primarily on sensory characteristics, MAP1 gas mixture was the most effective for stuffed mussel. According to sensory results, it has been determined that the control samples kept until the 11th day, while the MAP1 and the MAP2 groups kept until the 13th day. Of the chemical indices determined, the TVB-N values of MAP1 and MAP2 remained lower than the proposed acceptability limits of 20 mg N/100 g, up to 13 days of storage. Microbiological analysis results did not find any differences between the groups. It was found that the shelf life of air and MAP1-MAP2 packaged samples were 7 and 11 days, respectively.     

Effect of Modified Atmosphere Packaging on Quality and Shelf Life of Salted Bonito (Sarda sarda)

In this study, the fresh meat of bonito (Sarda sarda) was used to make lakerda, which is a type of salted fish (Turkish traditional product). The lakerda was packaged in plastic film (A), vacuumed (VP), placed in modified atmosphere packaging (MAP; M1 = 80%/20% CO₂/N₂, M2 = 65%/35% CO₂/N₂, M3 = 30%/60%/10% CO₂/N₂/O₂), and stored at 2 ± 1°C. Microbiological, chemical, sensory, and color analyses were conducted to determine the changes in quality. Total viable bacteria counts did not exceed the limit of consumption (7 log cfu/g) for all groups on Day 31. Total volatile basic nitrogen (TVB-N) and trimethylamine- nitrogen (TMA-N) values of M1, M2, and M3 remained lower than the proposed acceptability limits of 35 and 12 mg N/100 g, respectively, up to 31 days of storage. However, VP lakerda samples exceeded TVB-N limits after 31 days of storage, whereas A lakerda samples exceeded after 8 days of storage. In our study, sensory analysis determined the shelf life of modified atmosphere packaged lakerda. When Group A is compared with the other groups, MAP and VP lengthened the shelf life of lakerda by 23 days.     

Polyculture of the Giant Malaysian Prawn and the Golden Shiner in Southwestern Louisiana1

Juvenile prawns (Macrobrachium rosenbergii) were stocked at 37,050/ha and golden shiner (Noremigonus crysoleucas) fry at 321,100/ha into 16 earthen ponds at Rockefeller Wildlife Refuge, Grand Chenier, Louisiana. Four replicated treatments were tested: fed prawn monoculture, fed shiner monoculture, fed prawn and fed shiner polyculture, and unfed prawn fed shiner polyculture. The study lasted 149 days. There were no significant differences in growth between prawns fed in monoculture and prawns fed in polyculture (P > 0.05). However, fed prawns grew significantly larger (P < 0.05) than unfed prawns. Prawn survival in all treatments combined averaged 63%. Survival was significantly higher (P < 0.05) for fed prawns than for unfed prawns. Prawn yields averaged 533 kg/ha, when all treatments were combined. Yield was significantly higher (P < 0.05) for prawns grown with shiners and for prawns that received supplemental feed. Growth was significantly higher (P < 0.05) for shiners grown with fed prawns than for shiners grown with unfed prawns. Shiner survival averaged 33% and was significantly higher (P < 0.05) in monoculture than in polyculture. Yield for all ponds averaged 392 kg/ha, with no significant differences between treatments (P > 0.05).     

Targeted species substitution in giant freshwater prawn trade revealed by genotyping

This study presents the molecular barcoding results of giant freshwater prawns and allied products collected from inland landing centres, markets and stores of Vembanad Lake (Kerala state, India) which is recognized as a natural abode for Macrobrachium rosenbergii. Prawns collected from landing centres of the lake could be easily identified as the above with their large size and morphological characters. There were certain ‘alien’ prawns and prawn products (headless shell on, peeled and deveined) traded in the markets and stores of this region as M. rosenbergii. Genotyping of all these samples using COI and 16S rRNA gene sequences confirmed the speciation of individuals from inland landing centres as M. rosenbergii, ‘alien’ prawns and certain prawn products as M. malcolmsonii. To ensure the same and to detect the presence of any other congeners of genus Macrobrachium inhabiting Vembanad Lake, additional homologous COI and 16S rRNA sequences available in NCBI were acquired and incorporated for molecular analyses. Results generated from NJ tree and genetic distance data confirmed the trade of non‐indigenous Macrobrachium species M. malcolmsonii in Kerala for the first time and its use as a species substituent for M. rosenbergii.     

Effects of dietary mannan oligosaccharide on growth,survival, physiological,immunological and gut morphological conditions of black tiger prawn (Penaeus monodon Fabricius 1798)

The aim of this experiment was to determine the effects of dietary inclusion with mannan oligosaccharide (Bio‐Mos, Alltech, Nicholasville, KY, USA) on growth, survival, physiological and immunological conditions and gut morphology of the black tiger prawn (Penaeus monodon). Five diets supplemented with MOS at 0 g kg^?1 (control diet), 1, 2, 4 and 8 g kg^?1 were fed to the prawn juveniles (0.4 ± 0.06 g, total weight) for the duration of 63 days. Growth was the highest (P < 0.05) when the prawns were fed the 1 g kg^?1 MOS included diet. Wet tail muscle index (Tw/B), dry tail muscle index (Td/B) and tail muscle protein (Tmp) were higher (P < 0.05) in the prawns fed MOS included diets MOS compared with the prawns fed the control diet. Total haemocyte counts (THCs) of the prawns fed MOS included diets were higher (P < 0.05) than THCs of the prawns fed the control diet. Epithelium layer and epidermal cell density of the gut of the prawns fed 1 g kg^?1 and 2 g kg^?1 MOS diets were better than the prawns fed the control and other MOS diets. The results imply a positive effect of dietary supplementation of 1–2 g kg^?1 MOS in the culture of black tiger prawns.     

“太湖1号”杂交青虾规模化繁育技术研究

利用53hm2标准化鱼池,采用雌雄亲虾同池的放养模式与集中投放抱卵虾孵化培育模式2种模式进行“太湖1号”杂交青虾的规模化繁殖试验。结果显示,本期共繁殖生产虾苗33533．86万尾,31878．33kg。雌雄亲虾同池培育的产苗量比集中投放抱卵青虾培育的产苗量要低36．49～69．26kg／hm2,或132．85万。143．607万尾／hm2,苗种规格大小差异大。雌雄亲虾同池培育的捕苗时间从7月18日到8月25日,共计38d,集中投放抱卵亲虾培育池的苗规格较一致,捕苗时间为期25d,捕捞时间缩短了13d。这表明,集中投放抱卵虾孵化培育模式可作为青虾规模化繁殖生产的优选方式。     

Combined Effect of Ethanolic Coconut Husk Extract and Modified Atmospheric Packaging (MAP) in Extending the Shelf Life of Asian Sea Bass Slices

Combined impact of ethanolic coconut husk extract (ECHE) (200 ppm) and modified atmosphere packaging (MAP) with two separate gas mixtures [60% CO₂/30% N₂/10% O₂ (M1) and 80% CO₂/10% N₂/10% O₂ (M2)] on the shelf life of Asian sea bass slices during 4°C storage was investigated. Microbial load of slices was lowered when packaged under MAP, regardless of ECHE treatment, compared to the control (no ECHE treatment, packed in air). For control, slices treated with ECHE packaged in air, and samples packaged under M1, TVBC (total viable bacteria count) exceeded 6.0 log CFU/g at day 6, 9, and 12, respectively. TVBC of samples treated with 200-ppm ECHE and packaged under M1 and those packaged under M2 without and with ECHE treatment were lower than 6.0 log CFU/g at day 15. Peroxide and thiobarbituric acid reactive substances values in samples treated with ECHE, regardless of the packaging method, were lower than those kept under MAP and the control. Thus, shelf life extension of Asian sea bass slices could be achieved by treatment with 200-ppm ECHE in combination with M1 packaging, in which they could be stored longer than 15 days at 4°C.     

The Effects of Cold Plasma Application on Quality and Chemical Spoilage of Pacific White Shrimp (Litopenaeus vannamei) during Refrigerated Storage

Pacific white shrimp (Litopenaeus vannamei) is an important species in aquaculture worldwide. Post-mortem changes during cold storage reduce the quality of shrimp and shorten its shelf life. Cold plasma (CP) was applied for 45, 90, and 150s as T₁, T₂, and T₃, respectively, to fresh harvested shrimp. The biochemical parameters and melanosis were analyzed in comparison to metabisulphite treated (T_M) and control during 12 days of refrigerated storage. The results highlighted lower rate of increase in pH, total volatile base nitrogen (TVB-N) content, thiobarbituric acid reactive substances (TBARS), free fatty acid (FFA), peroxide value (PV), and fluorescent compounds (FC) in shrimp exposed to CP and metabisulphite compared to control (P < 0.05). Although CP lowered biochemical changes in T₁ and T₃ shrimp, T₂ was the most effective treatment in reducing undesirable changes and improving quality of shrimp. In all storage periods, melanosis was significantly lower in T₂, T₃, and T_M samples. Results demonstrate that CP exposure effectively decreases relative activity of polyphenol oxidase (PPO) enzyme, and prolonging the exposure to CP for 150 s resulted in 50% reduction in enzyme activity. We conclude that application of CP for 90 s was the most efficient circumstance to extend shelf life of white shrimp during cold storage.     

Effect of Holding and Packing Conditions on Hemolymph Parameters of Freshwater Prawns,Macrobrachium rosenbergii,during Simulated Waterless Transport

Preliminary market research has identified an unfulfilled market potential for live freshwater prawn, Macrobrachium rosenbergii, in urban areas of the USA and Canada. Truck transport is effective but requires shipment of large numbers of prawns to be economically feasible. Most retail markets are ill‐equipped to hold large quantities for subsequent live sales. Air‐freight of smaller quantities has potential but water weight limits its application. Shipping of live aquatic animals in waterless environments has been reported for some finfish and crustaceans. This project utilized biochemical characteristics of prawn hemolymph as measures of sublethal stress during simulated transport. Six trials were conducted to evaluate the effects of different variables involving preshipment holding conditions, acclimation prior to shipping, and conditions inside the shipping container. Trial 1 compared animals shipped in water with those in a non‐aqueous environment. Trial 2 compared three chilling rates (slow chill, fast chill, and no chill). Trial 3 evaluated different holding protocols including fed versus unfed, reduced pH, increased water hardness, and salinity. Trial 4 evaluated the addition of ammonia scavengers to the transport containers. Trial 5 evaluated the use of carbon dioxide scavengers and an anesthetic, AQUI‐S®. Trial 6 used the best results of Trials 2–5 in a combination of “Best Management Practices” (BMP) over extended time periods. Treatments had either three or four replications using Styrofoam boxes, each packed with six individually tagged prawns. Presoaked wood‐shavings and ice packs were used to keep the boxes moist and cool. The boxes were then sealed in individual oxygenated plastic bags. Trials 1–5 were conducted for 16 h and Trial 6 had separate boxes which were opened at 16, 24, and 32 h. Baseline hemolymph samples were taken prior to packing and from prawn alive at the end of all trials. Hemolymph variables included pH, pO₂, pCO_2, HCO₃, tCO₂, calcium, ammonia, osmolality, glucose, lactate, total protein, magnesium, calcium, and potassium. Percent survival and weight loss were also measured. Results of Trial 1 indicated that compared to transport in water, non‐aqueous environment significantly increased (P≤ 0.05) hemolymph levels of CO₂ and ammonia, and significantly reduced levels of oxygen. In Trial 2, survival in the Slow Chill treatment was significantly higher than in the No Chill treatment, although hemolymph characteristics were not impacted. In Trial 3 prawns held in tanks with added salt (17 ppt) had the highest survival and lowest hemolymph concentration of ammonia and partial pressure of CO₂. The ammonia scavengers in Trial 4 had no significant impact on survival or hemolymph variables. The CO₂ scavengers and anesthetic in Trial 5 had no statistically significant impact on survival. The BMP of Trial 6 consisted of, in the following order, holding in 17 ppt marine salt mix, slow chilling, anesthetic (AQUI‐S) dip, and adding limewater (Ca(OH)₂ + H₂O) to the shipping box as a CO₂ scavenger. In Trial 6, after 32 h of simulated “waterless” transport, prawns in the BMP treatment had significantly higher survival (96%) than prawns in the Control treatment (58%). The BMP prawns also had significantly higher partial pressures of oxygen and lower partial pressures of CO₂ in the hemolymph.     

Determination of the Tissue Distribution of PPO on Caramote Prawn (Melicertus kerathurus,Forskal, 1755) and Jinga Shrimp (Metapenaeus affinis,H. Milne Edwards, 1837) Caught from Izmir

Tissue distribution of polyphenol oxidase (PPO) was studied in caramote prawn (Melicertus kerathurus) and jinga shrimp (Metapenaeus affinis) postmortem. Activity was analyzed in different tissues: the head (cephalothorax + carapace), carapace, exoskeleton of the abdomen, pereopods, and maxillipeds, individually. Based on the results, PPO activity of jinga shrimp was determined to be higher than caramote prawn during the research period. Partial tissue distribution showed that the highest activity was determined in carapace by using 70% ammonium sulfate fractions. Partial tissue distribution was also used to determine the spread of black spots. In addition, comparison between the PPO levels of caramote prawn and jinga shrimp was performed. The importance of these species is their economic value. However, there is no available data in the literature about caramote prawn and jinga shrimp. The determined data showed us that using antioxidant chemicals would be suitable for jinga shrimp.