Chitosan Decelerates Melanosis in Shrimp: A Novel Technique for Visual Quality Assessment Using Digital Image Analysis

The study aimed to determine the effects of chitosan, sodium metabisulfite, and citric acid against melanosis, which causes significant economic losses during the storage of shrimps. For this purpose, two different types of chitosan were extracted from tiger prawn shell wastes. The extracted chitosan was characterized by viscosity, FT-IR, XRD, SEM imaging, and color analyses. Prevention of melanosis formation was investigated by testing chitosan, sodium metabisulfite, and citric acid. To achieve this, fresh deep-water pink shrimp samples immersed in different solutions were stored for 12 days at 4℃. Melanosis formation in the samples was observed via color measurement, sensory evaluation, and image analysis. According to the results of the research, the deacetylation degrees of chitosans were found to be 99.50 and 89.51% and 76.31 and 78.24% by two different methods, respectively. Viscosities were measured as 0.34 and 4.17 cSt, respectively. Regarding the color parameters, the L* values were 83.68 and 78.94, a* values were 0.55 and 2.71, and b* values were 10.33 and 13.85, respectively. According to the sensory evaluation conducted throughout the study, melanosis formation was observed in all groups starting from the 6th day. On the 8th day, the control groups exceeded the acceptability threshold, and on the 12th day, melanosis formation spread throughout the body in all groups. The sensory evaluation results were supported by the color measurement and image analysis implemented for the first time in this study. The present study’s results showed that chitosan obtained from shellfish wastes decelerates melanosis formation as an alternative to commercially used chemicals

Investigation of chemical, physical, microbiological and sensory changes during cold storage of anchovy marinades added chitosan.

TEZ9218Tez (Yüksek Lisans) -- Çukurova Üniversitesi, Adana, 2012.Kaynakça (s. 59-69) var.xiii, 71 s. : res. (bzs. rnk.), tablo ; 29 cm.Bu çalışmada, kitosanın hamsi (Engraulis encrasicolus) marinatlarının buzdolabında depolanması süresince kimyasal, fiziksel, mikrobiyolojik ve duyusal özellikleri üzerindeki etkisi araştırılmıştır. Marinasyon işlemi, kitosan grupları için, % 10 NaCl + % 1 ve % 0,5 kitosan (% 3 asetik asitte çözdürülmüş); kontrol grubu için % 10 NaCl + % 3 asetik asit solüsyonları ile 1:1.5 (balık:solüsyon) oranında 27 saatte yapılmıştır. Marinasyon işleminden sonra, hamsi filetoları buzdolabında 90 gün depolanmıştır. Marine edilmiş tüm hamsi gruplarında depolama süresince kimyasal, fiziksel ve duyusal değerlerde istatistiki olarak önemli düzeyde değişimlerin olduğu gözlenmiştir (p<0,05). TBA değeri bakımından kontrol grubu 70. gün tüketilebilirlilik sınırını aşarken, kitosan eklenen gruplar depolama süresince limit değerin altında kalmıştır. Peroksit değeri bakımından da gruplar arasında önemli farklılıklar gözlenmiş olup en yüksek değer kontrol grubunda belirlenmiştir (p<0,05). TVB-N değerinin depolama süresince tüm gruplarda düşük seviyelerde olduğu ve hamsi marinatlarında raf ömrünü belirleyici bir parametre olarak kullanılamayacağı tespit edilmiştir. pH değeri tüm gruplarda depolama süresince 4,5’in altında kalmıştır. Yine gruplar arasında L*, a* ve b* değerleri arasında depolamanın belirli günleri önemli farklılıklar gözlenmiştir (p<0,05). Marine edilen tüm gruplarda toplam bakteri sayısı çok düşük seviyelerde bulunmuştur. Duyusal değerlendirmeye göre, en iyi grup % 1 kitosan eklenen grup olurken, bunu sırasıyla % 0,5 oranında kitosan eklenen grup ve kontrol grubu takip etmiştir.This study investigates the effects of chitosan on chemical, physical, microbiological and sensory properties of anchovy (Engraulis encrasicolus) marinades during refrigerated storage. Marination process was performed with 10 % NaCl + 1% and 0.5 % chitosan solution (solved in 3% acetic acid) for chitosan groups and with 10 % NaCl + 3% acetic acid solution for control group at a rate of 1:1.5 (fish:solution) within 27 hours. After marination process, anchovy fillets were stored in a refrigerator for 90 days. Statistically significant changes were detected in chemical, physical, and sensory properties of all marinated anchovy groups during storage (p<0.05). Control group exceeded the consumable limit on the 70th day in terms of TBA value, while chitosan supplemented groups remained below the limit during storage. Significant differences were observed between groups in terms of peroxide values, and the highest value was detected in control group (p<0.05). It was determined that TVB-N values remained low in all groups during storage, and therefore, it cannot be used as a determinant parameter for shelf-life of anchovy marinades. pH stayed under 4.5 in all groups during storage. There were significant differences between groups in terms of L*, a* and b* values on certain days of storage (p<0.05). Total number of bacteria was found quite low in all marinated groups. In the sensory analysis, 1 % chitosan supplemented group was concluded as the best group, which was followed by 0.5 % chitosan supplemented group and control group, respectively.Bu çalışma Ç.Ü. Bilimsel Araştırma Projeleri Birimi tarafından desteklenmiştir. Proje No: SÜF2011YL5

Evaluation of the antibacterial activity of cultivated Caucasian whortleberry (Vaccinium arctostaphylos L.) against fish pathogens

Bacterial diseases are one of the major factors hampering aquaculture sustainability. Antibiotics are used widely to treat or prevent infectious bacterial diseases in aquaculture. However, because of growing problems of antibiotic resistance caused by the imprudent use of antibiotics, sourcing environmentally benign alternatives, such as herbal/medicinal plants, is now the focus of many researchers. Hence, in this study, a minimum inhibitory concentration (MIC) test with broth microdilution was performed to determine the in vitro antibacterial activity of an aqueous methanolic extract of cultivated Caucasian whortleberry (Vaccinium arctostaphylos L.) against various fish pathogens, i.e., Yersinia ruckeri, Pseudomonas putida, P. luteola, Aeromonas salmonicida, A. hydrophila, and A. sobria. The results revealed that the MIC values of the aqueous methanolic extract against Y. ruckeri, P. putida, P. luteola, A. salmonicida, and A. hydrophila were 8.75 mg mL−1, while against A. sobria it was 2.19 mg mL−1. This study indicated that the medicinal plant V. arctostaphylos L. can potentially be used against all the fish pathogens tested thanks to its various important bioactive compounds. However, to assess the potential of this plant, further in vivo studies should be carried out

Physical Properties of Refrigerated Anchovy Fillets Dipped with Natural Antioxidant Extract Isolated from Shrimp Shells

In this study, the effects of natural antioxidant extract isolated from the shells of giant red shrimp (Aristaeomorpha foliacea) on color properties of anchovy (Engraulis encrasicolus) fillets refrigerated storage were examined. Fish fillets were dipped into the following solutions as different treatments for 5 min: control containing only distilled water, 0.1 % and 0.5 % (w/v) crude antioxidant solutions and 0.005 % BHT solution. Then anchovy fillets were stored in the refrigerator during 18 days. The control and treated fillet samples were analyzed periodically for color (L*, a*, b*) analysis. Chroma and hue values were calculated. It was determined that shrimp shell extract (especially 0.5% group) and BHT has a positive effect on L* and a* values of anchovy (p0.05). Chroma value was the highest in group containing 0.5% of shell extract at the end of storage

Characteristics of Capoeta oguzelii, a new species of cyprinid fish from the Ezine Stream, Black Sea basin, Turkey (Teleostei: Cyprinidae)

WOS: 000428790500002Four species of Capoeta (C. baliki, C. banarescui, C. sieboldii and C. ekmekciae) have been reported from Black Sea drainages, to date. We recognised an additional species in the Ezine Stream in the Southern Black Sea basin. Based on the analysis of 21 metric and 8 meristic data, we concluded that the Ezine Stream population forms a distinct, unnamed species, which we have described as Capoeta oguzelii sp. n. This species can be distinguished from all other Capoeta species by the following combination of characteristics: small size, presence of only one pair of barbels, absence of a keratinised edge of the lower jaw, a weakly ossified last simple dorsal fin ray, 7-10 gill rakers on the first gill arch and 71/2 branched dorsal fin rays.http://www.zoobank.org/urn:lsid:zoobank.org:pub:066CC44A-3806-4DB7-8E88-AD971200E1EECentral Research Laboratory of Kastamonu University [2017/02]; Local Ethics Committee of Kastamonu University [2017/02]We are pleased to thank the Central Research Laboratory of Kastamonu University for supporting this study with microscope equipment. the study was approved by the Local Ethics Committee of Kastamonu University (Reference No. 2017/02)

Investigation of Different Deacetylation Degree of Chitosan Extracted From Shrimp Shell Waste

Introduction: Chitin and chitosan have been of interest in the past few decades due to their potential broad range of industrial applications. Due to its biodegradability, biocompatibility, nontoxic and wound healing properties and hemostatic activity, chitosan has received increased attention as one of the promising renewable polymeric materials for various applications. Because of those valuable specifications of chitosan are commonly uses in different sectors including especially food, chemistry, biotechnology, agriculture, veterinary, cosmetic, medicine, dentistry, environmental protection, textile, paper making and packaging. Material and Methods: In this study, crustacea shells were obtained from remains of food processing operations. Shells were competely separated from meat, organs and other discards, washed with tap water and dried at room temperature for 12 hours. For the extraction of chitosan deproteinization, demineralization and decolorization steps were carried out with 2.5N NaOH at 65 ºC for 6 h; 1.7 N HCl at 25 ºC for 6 h, and 1:9 hydrogenperoxide:shells threatened and then dried at 90 ºC for 2h, respectively. End of that processes prepared two different type of deacetylation degree of chitosan (low and high) and compared with physicochemical parameters. In order to determine basic physicochemical analysis of the chitosan; moisture and ash content, water and fat binding capacities, degree of deacetylation, molecular weight determination and viscosity, were measured with using AOAC, (1990), Wang and Kinsella, (1976), potentiometric titration methods, Wang et al., (2006), Automated Micro Viscometer (AVMn), respectively. Results: The results of the physicochemical parameters (deacetylation degree, moisture, ash, water and fat binding capacities, molecular weight, viscosity) of chitosan extracted from deep sea pink shrimp (Parapenaeous longirostris) shells are given as below. Degree of deacetylation were founded as 72.86% and 93.70%; the moisture contents were founded 1.80% and 1.52%; the ash contents were 0.12% and 0.18%; molecular weights were 14.08 kDa and 2.15 kDa; apparent viscosities were 1450 cP and 150 cP; water binding capacities were 808.17% and 654.16%, fat binding capacities were 910.23% and 692.30%, respectively. Discussion: In conclusion, oodles of crustacea shells have been discarded as wastes by seafood factory operations in the entire world. This has led to considerable scientific and technological interest in chitosan as an attempt to use these renewable wastes

Physicochemical characterization of chitosan extracted from Metapenaeus stebbingi shells

In this study, chitosan was extracted from Metapenaeus stebbingi shells. In order to determine physicochemical characteristics of the extracted chitosan, the yield, moisture and ash contents, degree of deacetylation, molecular weight, water and fat binding capacities, apparent viscosity and colour properties were measured using a variety of techniques including Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction. In addition, the physicochemical characteristics of the chitosan extracted from M. stebbingi shells were compared to commercial chitosan. The degree of deacetylation was calculated by the titration method and elemental analysis. The molecular weight was determined by viscosimetric methods. The results of the study indicate that shrimp shells are a rich source of chitosan as 17.48% of the shell's dry weight is consisted of this material. Extracted chitosan exhibited a lower molecular weight, higher degree of deacetylation, higher viscosity and higher water and fat binding capacities compared to the commercial chitosan

The Effectiveness of Different Treatments in Preventing Melanosis in Shrimp

The effectiveness of different treatments to prevent melanosis in fresh deepwater pink shrimp (Parapenaeus longirostris) was evaluated. Fresh shrimps were divided into six groups and immediately were dipped in tap water and acetic acid (control group 1 and 2), and solutions containing chitosan with high deacetylation degree and low deacetylaton degree, sodium metabisulphite, citric acid for ten minutes. After treatment the shrimps samples were packed and stored at +4°C. Melanosis index, sensory characteristics and colour parameters were determined periodically during the cold storage. Sodium metabisulphite showed strong properties of delaying melanosis development during cold stogare. The results of this study indicated that treatment with chitosan solutions did effect a statistically significant difference. In addition, the results showed that chitosan from shrimps wastes could be easily used instead of sodium metabisulphite

Metapenaeus stebbingi Kabuk Atıklarından Elde Edilen Kitosanın Buzdolabında Depolanan Alabalık (Oncorhynchus mykiss) Filetoları Üzerine Antimikrobiyal Etkisinin Belirlenmesi

Bu çalışmada, buzdolabı koşullarında (+4ºC) vakumlu ve vakumsuz ambalajlarda depolanan alabalık filetoları üzerine Metapenaeus stebbingi kabuk atıklarından elde edilen kitosanın antimikrobiyal etkisi araştırılmıştır. Kabuk atıklarından kimyasal yöntem kullanılarak ekstrakte edilen kitosanın karakterizasyonu sonucu, yüksek deasetilasyon derecesine (% 92.12) ve düşük molekül ağırlığına (2.20 kDa) sahip olduğu belirlenmiştir. Ekstrakte edilen kitosan ve ticari kitosanın farklı konsantrasyonlarının (% 0.1; 0.5; 1) alabalık filetolarına daldırma yöntemi ile eklendiği çalışmada, toplam bakteri, toplam koliform ve psikrofil bakterilerin değişimleri buzdolabında depolanma süresince izlenmiştir. Hem doğal hem de ticari kitosana daldırılan grupların 12 günlük depolama süresi boyunca kontrol grubuna göre mikroorganizma sayılarında azalma olduğu, en iyi sonucun % 0.1 doğal ve ticari kitosan uygulanan gruplarda elde edildiği tespit edilmiştir (p<0.05). Çalışma sonucunda, M. stebbingi kabuk atıklarından elde edilen kitosanın balıkların depolanması süresince antimikrobiyal katkı maddesi olarak kullanılabileceği belirlenmiştir.Bu çalışmada, buzdolabı koşullarında (+4ºC) vakumlu ve vakumsuz ambalajlarda depolanan alabalık filetoları üzerine Metapenaeus stebbingi kabuk atıklarından elde edilen kitosanın antimikrobiyal etkisi araştırılmıştır. Kabuk atıklarından kimyasal yöntem kullanılarak ekstrakte edilen kitosanın karakterizasyonu sonucu, yüksek deasetilasyon derecesine (% 92.12) ve düşük molekül ağırlığına (2.20 kDa) sahip olduğu belirlenmiştir. Ekstrakte edilen kitosan ve ticari kitosanın farklı konsantrasyonlarının (% 0.1; 0.5; 1) alabalık filetolarına daldırma yöntemi ile eklendiği çalışmada, toplam bakteri, toplam koliform ve psikrofil bakterilerin değişimleri buzdolabında depolanma süresince izlenmiştir. Hem doğal hem de ticari kitosana daldırılan grupların 12 günlük depolama süresi boyunca kontrol grubuna göre mikroorganizma sayılarında azalma olduğu, en iyi sonucun % 0.1 doğal ve ticari kitosan uygulanan gruplarda elde edildiği tespit edilmiştir (p<0.05). Çalışma sonucunda, M. stebbingi kabuk atıklarından elde edilen kitosanın balıkların depolanması süresince antimikrobiyal katkı maddesi olarak kullanılabileceği belirlenmiştir

The Effect of Using Chitosan obtained by Low Degree of Deacetylation in Laying Hen Diets

The present study was conducted to evaluate whether dietary chitosan with low degree of deacetylation (minimum %70) would affect laying performance and egg quality of layers. Thirty four weeks old laying hens were divided into 5 treatment groups of similar mean weight, comprising 14 birds each. The birds were fed standard layer diets containing 0, 200, 400, 800 and 1600 ppm low deacetylated chitosan for 8 weeks period. The birds were housed in individual cages in a complete randomized design. A 16:8 hours light:dark photoperiod was employed. Feed and water were given ad libitum. Laying performance was assessed by recording feed intake, egg weight, egg production daily; egg quality weekly. The results (Table 1) showed that low degree deacetylated-chitosan supplementation did not have significant (P>0.05) effects on feed intake, feed conversion ratio, body weight, egg quality parameters. The results suggest that different levels of dietary low degree deacetylated chitosan may not improve performance and egg quality of laying hens regardless of the supplementation levels