Valorisation of viscera from fish processing for food industry utilizations

Fish viscera is a valuable source of functional materials for the food industry, such as protein, oil, enzymes, protein hydrolysate, peptones, sterols, producing biodiesel, and other oleochemical industries. The major components of fish viscera are oil and protein, and their quantity depends on the fish habitats. Viscera oil from fish contains appreciable amounts of omega-3 fatty acids. The protein of fish viscera is a raw material for protein concentrates, hydrolysate, and bioactive peptides. All are valuable ingredients in food processing and product formulation. Most viscera are fish digestive tracts and organs responsible for producing enzymes, and several enzymes are found in high activity, such as lipases and proteases. The extraction of lipases and proteases from fish viscera and their utilizations have been intensively studied. Currently, the isolation of each major component from fish viscera is conducted separately. Therefore, it is challenging to obtain all valuable components from fish viscera to have a zero-waste process. This article reviews the separation of major components of fish viscera by conventional and emerging technology and the proposed simultaneous and integrative separation of all valuable major components.

Lesions caused by anisakid and capillariid in Cairina moschata raised on Marajó island, state of Pará, Brazil

ABSTRACT The Muscovy duck is a commercially important bird on the island of Marajó usually raised in a peculiar system that includes supplying fish viscera to the birds under semi-extensive farming conditions. This enables a risk of contamination and losses in the production of these birds, resulting from injuries caused by helminth infections, especially nematodes. The objective of this study was to evaluate the histopathological changes caused by nematodes of the genera: Eucoleus, Anisakis and Contracaecum. Thirty-three ducks with lesions in the esophagus and ventricle were analyzed. Histopathological exams showed a mild inflammatory infiltrate in the submucosa of the esophagus caused by the fixation of E. contortus and third stage larvae of Anisakis sp., and we recorded third stage larvae of Contracaecum sp. parasitizing the ventricle, this being the first record of this parasite in ducks in Brazil.

Physico-chemical aspects of Thai fermented fish viscera, Tai-Pla, curry powder processed by hot air drying and hybrid microwave-infrared drying

The objective of this research was to comparatively investigate the effect of hot air drying (HA) and hybrid microwave-infrared drying (MI) on physico-chemical characteristics of Thai fermented fish viscera, Tai-Pla, curry powder (TCP). HA was carried out at 60°C, 70°C, and 80°C and MI was carried out at a microwave power of 740, 780, and 810 W with a constant infrared heating power (500 W) for different drying times to obtain the final moisture content ≤ 12.0% and the water activity (aw) ≤ 0.6. The quality characteristics of TCP were governed by HA temperature and MI output power. TCP dried using HA and MI at all conditions had similar contents of protein, lipid, ash, fiber, and carbohydrate (p>0.05). The fastest drying rate was detected when MI at 810 W for 40 min was applied (p<0.05). In this condition, TCP had the lowest browning index (A294 and A420) and the highest lightness (L* value) (p<0.05). TCP dried with MI at all powers had higher phenolic content and lower TBARS compared to HA (p<0.05). However, no significant differences in DPPH• scavenging activity were observed among TPC made by HA and MI (p>0.05). Similar Fourier transform infrared (FTIR) spectra with different peak intensities were observed in all samples, indicating the same functional groups with different contents were found. The bulk density of all TCP ranged from 0.51 g/mL to 0.61 g/mL and the wettability ranged from 24.02% to 26.70%. MI at 810 W for 40 min effectively reduced the drying time (5-fold faster) and lowered the specific energy consumption (18-fold lower) compared to the HA at 60°C for 210 min. Therefore, MI is a promising drying technique to reduce the drying time and improve the overall quality of TCP.

EXTRACTION OF COLLAGENOLYTIC ENZYME FROM FISH VISCERA BY PHASE PARTITIONING (PEG/CITRATE) AND ITS POTENTIAL FOR INDUSTRIAL APPLICATION

Internal viscera fish are potential sources of protein biomolecules of biopharmaceutical interest. However, this residue is frequently discarded inappropriately. The possibility to obtain by products of higher added value is a reality. Inside this view attention must be given to processes for the recovery and extraction of target molecules. However, the high cost of processing these residues is one of the obstacles to their reuse; techniques that facilitate their handling and make the process cheaper are desirable, such as extraction in a two-phase aqueous system. Thus, the aim of this study was to extract collagenolytic enzymes from common snook (Centropomus undecimalis) using a two-phase aqueous system (polyethylene glycol/citrate), according to the 24 factorial design, using as variables: molar mass of PEG (MPEG), PEG concentration (CPEG), citrate concentration (CCIT), pH, still, considering purification factor (FP), partition coefficient (K), and yield (Y). The collagenolytic activity of the crude extract was 102.41 U mg-1, after partitioning, was purified 3.91 times (MPEG: 8000; CPEG: 20.0%; CCIT: 20.0% and pH 6.0). Inhibition (U mg-1) was observed in benzamidine (22.51), TLCK (21.05), TPCK (21.29), and PMSF (23.05), signaling to be a serine-protease. The results showed the advantage of this semipurification technique as concerns to the low cost of extraction and purification, adding value to the fishing source material and allocating the residues from its processing to the industry.

Screening of Ciguatoxins in the Philippines by Animal Assay: Symptoms, Levels, and Distribution in Fish Tissue

The Philippines is an archipelagic country that belongs to the biologically diverse Pacific Coral Triangle, rich in marine resources, including corals, reef fishes, and algae. This explains the continuous sustenance of the Filipinos on fish as a major protein source. Despite their contribution to human consumption, some commercially important coral reef fishes are a threat to food safety, compromising public health. Currently, ciguatera fish poisoning (CFP) has been focused on by scientists since it is the most frequently reported seafood-toxin illness in the world acquired from contaminated coral reef fishes. The present study investigates the contamination of reef fishes in the West Philippine and Sulu Seas using animal assay. Ciguatoxins (CTX) are present in commercially important reef fishes such as barracuda (Sphyraena barracuda), parrotfish (Scarus quoyi), rabbitfish (Siganus guttatus), grouper (Plectropomus leopardus), moray eel (Gymnothorax melanospilos), and snapper (Lutjanus campechanus). Scarus quoyi had the highest toxicity of 0.65 ± 0.55 ppb and 0.48 ± 0.36 ppb found in flesh and viscera, respectively. Although higher toxicities were observed from fish viscera, toxicities between fish parts did not vary greatly (p > 0.05). Positive samples exceeded the 0.01 ppb guideline established by the US Food and Drug Administration and the Philippines’ regulatory limit set by the Bureau of Fisheries and Aquatic Resources. Symptoms of mice showing the presence of Pacific CTX-1 were noted. Since mouse bioassay was used in screening reef fishes that pose non-specificity and insensitivity problems, the researchers suggest that analytical methods must be used in characterizing and quantifying these types of toxins. Establishing the methodologies in detecting CTX would greatly help monitor and manage CFP in commercially identified reef fishes in the country.

Anisakidae Skrjabin & Karokhin, 1945 and Raphidascarididae Hartwich, 1954 nematodes in lutjanidae (pisces: perciformes) from the Brazilian Northeast Coast

The present study aimed at describing and evaluating the fauna of Anisakidae and Raphidacarididae nematodes of lutjanid fish (snappers) from the Brazilian northeastern coast unloaded at the city of Aracaju, capital of the State of Sergipe. A total of 186 lutjanids of 5 different species were analyzed including 69 Lutjanus analis, 51 L. vivanus , 29 Ocyurus chrysurus, 23 L. synagris, and 14 L. jocu. Nematode specimens found in the viscera of these fish were clarified with lactophenol. Illustrations of each of these specimens were prepared to help identify these samples and compose their taxonomic description and classification. At necropsy, 3,183 nematodes belonging to two families were collected from fish viscera which included the following: Anisakidae: Anisakis, Terranova , Contracaecum, and Goezia; Raphidascarididae: Raphidascaris (Ichthyascaris) and Hysterothylacium . A total of six genera of nematodes were found at postmortem examination of which adult worms of only three genera (Goezia, Raphidascaris and Hysterothylacium) were detected in the fish examined. Larvae of Terranova sp. were found only in the musculature of O. chrysurus . Most of the nematode larvae were present in the mesentery and organs of the fish necropsied. Therefore, the zoonotic potential of these nematodes cannot be ruled out. There was a significant negative correlation between the intensity of parasitism by anisakids and the total body length of O. chrysurus; the intensity of parasitism was greater in smaller and shortef fish. There was a significant positive correlation between the abundance of these parasites and the length of L. synagris; the presence of these parasites increased according to the fish’s body length. To the authors’ knowledge, these are the first records of Raphidascaris (Ichthyascaris ) sp. and Hysterothylacium sp. in L. vivanus , of Terranova sp. in O. chrysurus and L. jocu, and of Goezia sp. in L. analis. These novel findings add the Brazilian northeast coast and the State of Sergipe in the geographic distribution of these parasites in the country.