Comparative Effects of Fish and Cow Gelatins and Locust Bean Gum on Chemical,Textural, and Sensory Properties of Yogurt

ABSTRACT

Yogurt is a traditional dairy product widely consumed all over the world. Syneresis, which is a result of lower water holding capacity, is a big concern and an important quality parameter. In this study, the efficiency of locust bean gum and different gelatins (fish skin, fish scale, and bovine skin) in preventing syneresis was investigated. Samples were stored at 4°C for 2 weeks, a typical shelf life of yogurt, and analyzed periodically for quality parameters. Syneresis, viscosity, and water holding capacity of the control and gum added samples were almost identical, while gelatin added samples were generally significantly improved (p < 0.05).     

The Effect of Sodium Caseinate Coating Incorporated with Zataria moltiflora Essential Oil on the Quality and Shelf Life of Rainbow Trout During Refrigerated Storage

ABSTRACT

In the present study, aqueous solutions of sodium caseinate (SC) 8% (w/w) were provided in the form of four treatments—including SC without any essential oil (EO) as well as SC with 0.25, 0.5, and 1% (v/w) concentrations of Zataria moltiflora EO. Fish samples were treated with aqueous solutions and stored at 4 ± 1°C for 20 days. The control and treated fish samples were analyzed for chemical (total volatile basic nitrogen, pH, thiobarbituric acid, peroxide value), microbiological (total viable count and psychrotrophic count), and sensory analyses every 4 days. Based on results, SC edible coating had no antimicrobial effect but acted like a barrier against the fish flesh contamination. Moreover, incorporating Zataria moltiflora EO with SC edible coating reduces peroxide value and thiobarbituric acid-reactive substances values as well as the chemical and microbiological spoilage of refrigerated ?sh samples. Furthermore, sensory evaluation results showed that the presence of thyme oil improved the sensory quality of the rainbow trout.     

Effects of Bicarbonate,Xanthan Gum,and Preparation Methods on Biochemical,Physicochemical, and Gel Properties of Nile Tilapia (Oreochomis niloticus Linn) Mince

This study was aimed to determine the effects of phosphate compound substitutions (sodium bicarbonate and xanthan gum) and preparation methods—headed, gutted whole fish, and mince; fresh and after frozen storage (?20°C for 3 months)—on Nile tilapia mince qualities. Results showed that bicarbonate (0.3% with 8% sucrose/sorbitol) is an efficient phosphate compound replacement as evidenced by the comparative values of salt extractable protein, Ca²⁺-ATPase activity, total sulfhydryl content, and textural properties to those of the phosphate-added—0.3% sodium tripolyphosphate (STPP) with 8% sucrose-sorbitol—sample after 3-month frozen storage (p > 0.05). Both cryoprotected samples containing STPP or bicarbonate exhibited higher denaturation temperatures of myosin than others. Xanthan gum (0.5%) could neither stabilize the biochemical and physicochemical properties of mince during 3-month frozen storage nor improve textural properties of gel from frozen whole fish.     

Development of Intermediate Moisture Fish Patties from Minced Rockfish Meat (Sebastes sp.)

Abstract

An Intermediate Moisture (IM) fish patty was formulated from rockfish mince (85.7%), sorbitol (6.0%), soy protein isolate (2.0%), tapioca starch (2.0%), chicken bouillon (1.3%), refined salt (2.5%), and dried seasonings (0.5%). The mixture was dehydrated at 40 °C for 10 h and vacuum packaged. The dried product had a moisture content of 33% and a water activity of 0.82. The desorption isotherm was sigmoid in shape indicating water activity of the product at ambient temperature in the Philippines would remain stable. Seasonings were added to improve the taste and possibly the stability of the product. Sorbitol addition improved the texture, as judged by a sensory panel, as well as the rehydration index of the patties. Humectat and seasonings improved the overall acceptability of the patties by a sensory panel. Product was prepared with and without preservatives (potassium sor-bate and TBHQ), dehydrated at 40 °C for 10 h, vacuum packed and held at 38°C or ?20°C for two months. Moisture content, water activity, pH, rehydration index, TEA value, Hunter-Gardner color, texture profile, amino acid composition, sensory properties and microbial growth were determined at storage intervals. Instrumental and sensory tests showed no significant differences (p < 0.05) among samples stored with or without preservative and at ?20°C vs. 38°C.     

Properties of Fish Sausages Containing Common Carp (Cyprinus carpio) Roe Oil and Defatted Roe Protein Hydrolysate during Refrigerated Storage

Influence of emulsified or non-emulsified common carp roe oil (CRO) and carp defatted roe hydrolysate (CDRH) on properties of crucian carp (Carassius auratus) sausages was determined during 30-day storage at 4°C. Sausages containing CRO and CDRH were lighter and had better textural properties including hardness, gumminess, and chewiness. These textural attributes were significantly higher in the sample prepared with pre-emulsified CRO and 7 g/100 g CDRH (p < 0.05). The sausages fortified with CDRH also presented better microstructure, as evidenced by fewer voids and smaller oil droplets. When incorporated at 7 g/100 g, CDRH could significantly reduce microbial spoilage in sausages in terms of the total viable count and the psychrophilic bacterial count (p < 0.05); however, pre-emulsification had no significant effect on antibacterial activity of hydrolysate in the samples (p > 0.05). Sausages with pre-emulsified roe oil and 7 g/100 g hydrolysate were more resistant against lipid oxidation and had a higher level of polyunsaturated fatty acids, especially docosahexaenoic acid and eicosapentaenoic acid after 30 days of storage at 4°C. Furthermore, the sausages with pre-emulsified CRO and 7 g/100 g CDRH exhibited better organoleptic properties at day 30.     

Production of Interesting Peptide Fractions by Enzymatic Hydrolysis of Tuna Dark Muscle By-Product Using Alcalase

ABSTRACT

A protein hydrolysate was prepared from proteins of tuna dark muscle by-product. The hydrolysis conditions (time, temperature, pH, and enzyme concentration) using Alcalase was optimized by response surface methodology (RSM). The regression coefficient close to 1.0, observed during experimental and validation runs, indicated the validity of the model. The hydrolysate produced under the optimum conditions determined by RSM has a low rate of peptide fraction of molecular weight of 4–1 kDa. Meanwhile, the results obtained by hydrolysis under optimal conditions determined by a complementary study (temperature 55°C, time 60 min, 1% enzyme concentration, and pH 8.5) show that the hydrolysate produced has a height rate of the peptide fraction of molecular weight of 4–1 kDa. The amino acid composition of the protein hydrolysate prepared proved to have the potential for application as an ingredient in balanced fish diets and as a source of nitrogen in microbial growth media.     

Using Antioxidants for Extending the Shelf Life of Frozen Nile Karmout (Claries lazera) Fish Mince

Abstract

Nile karmout (Claries lazera)fish mince was treated with 0.5% sodium tripolyphosphate (STPP), 0.5% ascorbic acid, 0.5% citric acid, and 0.1% Na EDTA, then stored at -18°C for 6 months. Yield, proximate composition, thiobarbitunc acid value (TBA), free fatty acid (FFA), salt soluble protein (SSP), non-protein nitrogen (NPN), water holding capacity (WHC), and cooking loss were determined at 0, 2, 4, and 6 months of storage. The yield of skinned fillet from whole fish was 47.0%. Moisture, protein, fat and ash offish mince were 72.9%, 17.6%, 8.5% and 1.0%, respectively. TBA values and FFA levels indicated that ascorbic acid and Na₂EDTA were the most effective antioxidants. Samples treated with STPP had the highest salt soluble protein. STPP was effective in maintaining the WHC of treated sample. Samples treated with citric acid had the highest cooking loss. Results of the study suggested that karmout is an excellent source for producing fish mince for further processing. Samples treated with antioxidants retarded the rancidity during frozen storage.     

Impact of Wall Material on the Physiochemical Properties and Oxidative Stability of Microencapsulated Spray Dried Silver Carp Oil

This study aimed to microencapsulate silver carp oil by spray drying with different combinations of wall materials (gum Arabic, modified starch Hi-cap, maltodextrin, and inulin) and evaluate the effects of these combinations on the physiochemical and oxidative stability of the microcapsules. Feed emulsions were also investigated prior to spray drying. Modified starch-based microcapsules had higher encapsulation efficiency (91.22-92.78%) and yield (87.41-92.15%), excellent solubility (91.85-93.67%), good particle size (301.20-407.73 d.nm), color, and powder morphology. The presence of inulin reduced agglomeration in powders. All the powders exhibited good protection against lipid oxidation during 2 months of storage, whereas the modified starch and inulin combination provided the best stability.     

Effect of Storage Conditions on Total Volatile Base Nitrogen Determinations in Fish Muscle Extracts

Total volatile base nitrogen (TVBN) is a widely used fish spoilage indicator. Because TVBN is typically measured from muscle extracts, analytical laboratories would benefit from understanding how different conditions for storing extracts affect TVBN results. To examine this question, extracts from the muscle of gilthead sea bream (Sparus aurata) were prepared and stored. Different storage temperatures (4,??20, and??80°C) and storage periods (7 days to 2 months) were tested. To compare how well the different storage conditions worked for different TVBN levels, the study took advantage of the fact that TVBN values change depending on how long the gilthead sea bream is stored before extracts are prepared. Extracts were prepared from fish maintained in ice for 0, 4, and 10 days postmortem. Comparing the storage conditions tested, all offered statistically identical results independent of the storage period and temperature. Nevertheless, only the extract maintained at 4°C for 7 days achieved statistically equal values to not stored extracts.     

Dietary lipid sources affect the performance of Nile tilapia at optimal and cold,suboptimal temperatures

Five sources of dietary fatty acids (fish, linseed, sunflower, olive and coconut oils) were evaluated in juvenile Nile tilapia in two trials: at optimal (28°C) and suboptimal (22°C) temperatures lasting 9 and 12 weeks, respectively. At 28°C, there was no clear effect of dietary source on fish growth, but at 22°C, the highest daily weight gain occurred in fish fed sunflower, linseed and fish oil. Feed efficiency and apparent net protein utilization increased as the amount of unsaturated fatty acids, especially n‐3 polyunsaturated fatty acids (PUFA), in the diet increased. Coconut oil, which is rich in saturated fatty acids (SFA), led to the worst growth results, especially at 22°C, with the lowest weight gain, feed intake and feed utilization by tilapia. The body fatty acid profile, in % of total fatty acids, was dependent on diet composition. However, for all treatments, PUFA body content increased with the decrease in temperature, but SFA and monounsaturated fatty acids remained the primary contributors to the body profile. Either fish oil or vegetable oil may be used as sources of dietary fatty acids for Nile tilapia, but at suboptimal temperatures, a dietary source containing more PUFA and less SFA improves performance.     

Preparation and Storage Characteristics of Ribbon Fish Laminates

Abstract

A process to prepare dehydrated laminates of ribbon fish is reported. Pieces of eviscerated and beheaded fish were pressed under a screw press and the laminates obtained were subjected to air drying at 55°C for 14 hr. The product was golden brown in color, and had 18.4% moisture, 22% rehydration capacity, and pepsin and trypsin digestibilities of 51 and 62%, respectively. Oxidation of lipids during aerobic storage of the product at ambient temperature could be controlled by vacuum packaging. Sensory evaluation of the productfried in vegetable oil after Serobic storing at ambient temperature for 100 days suggested its acceptability. The process has potential for value addition of ribbon fish.     

Textural and Sensory Properties of Fish Sausage from Rainbow Trout

The aim of this study was to determine the textural and sensory properties of fish sausage which were prepared from refrigerated and frozen rainbow trout (Onchorynchus mykiss) and stored for 14 days at 0?4 °C. These two groups of sausages were compared for texture, physical, and sensory properties by carrying out texture profile analysis (TPA), shear test, water holding capacity (WHC), cook loss, color, and sensory analyses. According to TPA and shear test, sausages prepared from frozen fillets exhibited a texture significantly (p < 0.05) weaker than those prepared from refrigerated fillets, but no difference in overall liking was observed.     

Gel Forming Ability and Other Properties of Eleven Underutilized Tropical Marine Fish Species

Abstract

The gel forming ability and other characteristics of the mince of 11 underutilized marine fish were studied. They were Bombay duck, silverbelly, sea catfish, silver jewfish, jewelled shad, queenfish, Spanish mackerel, hardtail, Indian tuna, tripletail and false conger eel. Mince was prepared from fillet and a portion of the mince was washed two times with cold water (5°C) containing 0.1% NaCl. Both washed and unwashed mince were ground with 3% NaCl. Ground paste was then stuffed into plastic tube and heated for one- and two-step heating. In the one-step heating, the tubes were subjected to 25°, 30°, 35°, 40°, 50°, 60°, 70° and 80°C for 60, 120 and 180 min. In the two-step heating, the tubes were pre-heated at 25°, 30°, 35°, 40°, 50°, 60°, 70° and 80°C for 60, 120 and 180 min. After the pre-heating, the tubes were immediately subjected to 85°C for 30 min. The gel was subjected to puncture, folding, expressible moisture and sensory tests.

Two-step heating distinctly improved the gel strength compared to the one-step heating. The improvement due to two-step heating was more at low preheating temperatures from 25-35°C. Washing improved the texture and color of all of the gels except Bombay duck and decreased the extent of gel-disintegration in silverbelly, queenfish, sea catfish and hardtail. The gels were set optimally at 35°-40°C for most species. Species variation in the disintegration of the gels was observed. Bombay duck mince produced very weak gel. Neither two-step heating nor washing could improve the gel quality of Bombay duck mince. Our data suggested that jewelled shad, queenfish, silver jewfish, sea catfish, tripletail and false conger eel could be suitable as the material for surimi.     

Histamine and Histidine in New Zealand Marine Fish and Shellfish Species,Particularly Kahawai (Arripis trutta)

Forty-seven retail samples of fish (28 species) were tested for levels of free histidine, histamine and aerobic plate counts. Five samples had elevated levels (≥ 20 mg/100 g) of histamine and all had < 100 mg/100 g. Three species had free histidine levels of more than 1000 mg/l00 g and these have been implicated in scombroid poisoning in New Zealand. One species with high histidine levels, kahawai (Arripis trutta), was chosen to determine the conditions under which potentially hazardous levels of histamine might develop. Two trials were carried out in which kahawai were stored under 17 regimes at temperatures between 0 and 35°C. For 10 of these treatments the fish were transferred from elevated storage temperatures to refrigerated storage during the trials. Levels of histidine and histamine, aerobic plate counts at 20°C and 35°C and sensory quality were monitored. The levels of free histidine in kahawai varied with season, and in Trial 2 there was a net loss of histidine + histamine during storage. Bleeding kahawai did not significantly affect the levels of histidine. Histamine levels varied greatly in fish held under identical conditions. Fish held at ambient temperatures developed the highest levels of histamine. Elevated histamine levels (> 20 mg/100 g) were first recorded in fish stored for 0.9, 0.9, 1, 2, 2.7, and 8 days at 35, 30, 25, 20, 15 and 10°C respectively. Storage at 5°C after storage at higher temperatures did not result in elevated levels. Of the 59 samples with elevated histamine levels, 9 had acceptable sensory characteristics while all had aerobic plate counts exceeding 10⁶ colony-forming units/g. Aerobic plate counts at 20°C are recommended over those at 35°C. It is concluded that fresh kahawai will only present a hazard from scombroid poisoning under conditions of extreme temperature abuse and that the presence of high numbers of bacteria is a good indicator of the hazard while sensory quality is not.     

Optimization of Hydrolysis Conditions for Production of Gelatin Hydrolysates from Shark Skin Byproduct and Evaluation of Their Antioxidant Activities

ABSTRACT

The effect of Alcalase hydrolysis conditions on antioxidant activities of shark skin gelatin hydrolysate (SSGH) byproduct was studied. Optimal hydrolysis condition for SSGH at 60°C, pH 7.5, and 2.70 AU kg^?1 gelatin protein was used for varied hydrolysis times (10–90 min). The IC₅₀ against DPPH radicals of SSGH hydrolyzed for 90 min (SSGH-90) was 27.39 mg ml^?1, which is greater than ascorbic acid. SSGH-90 was predominantly composed of 15–20 kDa protein fragments that regulated increases in peroxide value and thiobarbituric acid reactive substances values and suppressed decrease in DHA of a fish oil-in-water emulsion during storage at 30°C for 7 days.     

Oxidative Stability of Spray-Dried Microencapsulated Fish Oils with Different Wall Materials

Multilayer microencapsulation of fish oil was evaluated by using fish gelatin (treated with or without microbial transglutaminase [MTGase]), chitosan, and maltodextrin for its ability to control lipid oxidation. This study showed that a mixture containing gelatin and maltodextrin obtained the highest percentage of core release. The oxidative stability of the formulated mixtures and the bulk oils was investigated during a period of 60 days. The peroxide value (PV) was assessed as a parameter for primary oxidation products, and p-anisidine (p-AV) and thiobarbituric acid reactive sub-stances (TBARS) was used to analyze secondary oxidation compounds. Observation of oxidation products showed that combinations of gelatin and maltodextrin made by adding MTGase and a mixture of gelatin and chitosan were able to increase the oxidative stability, and increases in PV and p-AV and TBARS were found for all oils.     

Antioxidative Activitiy of Protein Hydrolysate from the Muscle of Common Kilka (Clupeonella cultriventris caspia) Prepared Using the Purified Trypsin from Common Kilka Intestine

Trypsin from the intestine of common kilka (Clupeonella cultriventris caspia) was purified using ammonium sulfate precipitation (30–50% saturation), Sephadex G-75, and DEAE-cellulose chromatography with the purity of 30-fold and the yield of 12%. The molecular weight of trypsin was estimated to be 23.2 kDa based on sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The trypsin had optimal activity at pH 8.0 and 60°C using N-α-benzoyl-DL-arginine-ρ-nitroanilide hydrochloride (BAPNA) as a substrate and showed high stability in the pH range of 7.0–10.0. It was stable up to 50°C. Soybean trypsin inhibitor (SBTI) and N-ρ-tosyl-L-lysine-chloromethylketone (TLCK) significantly inhibited trypsin activity (p < 0.05). Protein hydrolysate from common kilka muscle with different degrees of hydrolysis (DHs; 20, 30, and 40%) was prepared using the purified trypsin, and antioxidative activities were determined. 1,1-Diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities, ferric reducing antioxidant power, and ferrous chelating activity of hydrolysate increased with increasing DH up to 40% (p < 0.05). Therefore, trypsin from intestine of common kilka could be used as a processing aid for production of fish protein hydrolysate with antioxidative activity.     

Changes During Chilled Storage of Whole Tilapia and Short-Term Frozen Storage of Tilapia Fillets

This study evaluated the physicochemical changes in Nile tilapia (n = 82, 373.71 ± 61.91 g) refrigerated for up to 92 h and in the frozen fillets. The tilapias were captured with nets, slaughtered by ice and water shock (1:1) in a temperature of approximately 2°C for 30 min, and stored refrigerated at 4°C in polystyrene boxes containing ice. The fish were filleted, and filets were weighed and frozen. The drip loss and protein were determined after 23 days of frozen storage. After 4 h of storage, all fish were in full rigor mortis. The pH of the muscles decreased for up to 45 h of the storage period. The fillets obtained from tilapia stored for more than 72 h lost more weight and protein. Thus, the filleting or processing of tilapia should be done before 72 h of cold storage, since deterioration of the fish starts to occur after this period.     

Fish oil substitution by soybean oil in Sharpsnout seabream Diplodus puntazzo: Performance,fatty acid profile,and liver histology

The present study was conducted to determine the effect of soybean oil on the performance and liver histology in Sharpsnout seabream (Diplodus puntazzo) (initial body mass 35 g). Four experimental diets were formulated containing 0%, 25%, 50%, and 75% of soybean oil substituting fish oil. Fish were fed for 84 days. Increasing the level of soybean oil had no significant effects on growth and feed efficiency parameters. Biometrics, body composition, protein efficiency, and energy efficiency were not affected by the fish oil replacement. Muscle and liver fatty acids reflected fish oil substitution. Moreover, histology did not show statistical differences among treatments. Sharpsnout seabream juveniles can be fed with diets in which fish oil has been replaced with soybean oil at up to 75% of total lipid in the diet for a period of 84 days without affecting growth, feed efficiency, biometric parameters, and body composition.     

Development of Dry Artificial Fish Bait for Trap Fishing Using Tuna Red Meat and Shrimp Head Wastes

ABSTRACT

This study developed and evaluated dry artificial fish bait for trap fishing utilizing tuna red meat (TRM) and shrimp head powder (SHP), aiming to replace the usage of edible fishes, such as sardines and squids, as bait. A total of 23 dry baits were prepared and tested for stability in seawater and acceptance by tilapia. Based on the stability and acceptability test results, two baits were selected as ideal and were further tested for protein leaching and dry matter loss in seawater. The tests revealed that the stick-shaped bait containing 61% TRM and 15% SHP was the ideal bait, with a protein leaching rate of 24.82 mg/g/h and dry matter loss of 36.6 mg/g/h. The catch rate of the traps baited with the artificial fish bait was significantly higher (P < 0.05) than those baited with squid meat (17 Nos/trap) and sardines (23 Nos/trap). Further, the catch rate of traps baited with artificial bait (38 Nos/trap) was found to be comparable with those baited with raw shrimp head wastes (SHW) (40 Nos/trap). When the bait was concentrated with 0.1% sodium benzoate, shelf life was extended by up to 6 months.