Impact of the Covering Vegetable Oil on the Sensory Profile of Canned Tuna of Katsuwonus pelamis Species and Tuna’s Taste Evaluation Using an Electronic Tongue

The impact of the covering vegetable oil (sunflower oil, refined olive oil and extra virgin olive oil, EVOO) on the physicochemical and sensory profiles of canned tuna (Katsuwonus pelamis species) was evaluated, using analytical techniques and a sensory panel. The results showed that canned tuna covered with EVOO possesses a higher content of total phenols and an enhanced antioxidant capacity. This covering medium also increased the appreciated redness-yellowness color of the canned tuna, which showed a higher chromatic and intense color. Olfactory and kinesthetic sensations were significantly dependent on the type of oil used as covering medium. Tuna succulence and adhesiveness were promoted by the use of EVOO, which also contributed to decreasing the tuna-related aroma sensations. The tuna sensory data could be successfully used to identify the type of vegetable oil used. Moreover, a potentiometric electronic tongue allowed discriminating between the canned tuna samples according to the vegetable oil used (mean sensitivity of 96 ± 8%; repeated K-fold cross-validation) and the fruity intensity of the EVOO (mean sensitivity of 100%; repeated K-fold cross-validation). Thus, the taste sensor device could be a practical tool to verify the authenticity of the declared covering medium in canned tuna and to perceive the differences in consumers' taste.

PENGARUH PERBEDAAN PENAMBAHAN TEPUNG UBI JALAR KUNING (Ipomoea batatas L) DAN DAGING IKAN CAKALANG (Katsuwonus pelamis) TERHADAP NILAI GIZI DAN SENSORIK BISKUIT

ABSTRACTThe aim of the study was to determine the effect yellow sweet potato flour (Ipomoea batatas L) and skipjack tuna (Katsuwonus pelamis) addition on the nutritional and sensory values of biscuit products. This research was conducted using a completely randomized design (CRD) method with various formulation treatments, namely K0 (100% wheat flour), K1 (75% yellow sweet potato flour: 5% fish meat: 20% wheat flour), K2 (70% yellow sweet potato flour: 10% fish meat: 20% wheat flour), K3 (65% yellow sweet potato flour: 15% fish meat: 20% wheat flour), and K4 (60% yellow sweet potato flour: 20% fish meat: 20% wheat flour). The data were analyzed using analysis of variance, with further testing using Duncan's multiple range test (DMRT) at a 95% confidence level. The results show that the K1 treatment was the most preferred treatment by the panelists with hedonic rating scores of color, aroma, taste, and texture reached 4.34 (like), 4.16 (like), 4.13 (like), and 4.09 (like), respectively. Nutritional value analysis of the selected K1 biscuit products shows that it contained 6.87% water, 2.83% ash, 26.17% fat, 6.58% protein, and 57.83% carbohydrates. The biscuit product with the addition of yellow sweet potato flour and skipjack fish meat met the national standard for fat and protein contents. Keyword: Biscuit, yellow sweet potato flour, skipjack meatABSTRAKPenelitian bertujuan untuk mengetahui perbedaan penambahan tepung ubi jalar kuning (Ipomoea batatas L) dan daging ikan cakalang (Katsuwonus pelamis) terhadap nilai gizi dan sensorik produk biskuit. Penelitian ini dilakukan dengan menggunakan rancangan acak lengkap (RAL) dengan berbagai perlakuan formulasi, yaitu K0 (Tepung terigu 100%), K1 (Tepung ubi jalar kuning 75% : daging ikan 5% : tepung terigu 20%), K2 (Tepung ubi jalar kuning 70% : daging ikan 10% : tepung terigu 20%), K3 (Tepung ubi jalar kuning 65% : daging ikan 15% : tepung terigu 20%), K4 (Tepung ubi jalar kuning 60% : daging ikan 20% : tepung terigu 20%). Data hasil penelitian dianalisis menggunakan sidik ragam (analysis of varian), dengan uji lanjut menggunakan duncan’s multiple range test (DMRT) pada taraf kepercayaan 95%. Hasil penelitian menunjukan bahwa perlakukan K1 merupakan perlakuan yang paling disukai oleh panelis dengan skor penilain hedonik warna 4,34 (suka), aroma 4,16 (suka), rasa 4,13 (suka) dan tekstur 4,09 (suka). Analisis nilai gizi produk biskuit terpilih K1 meliputi kadar air (6,87),abu (2,83), lemak (26,17), protein (6,58) dan karbohidrat (57,83). Berdasarkan standar mutu SNI biskuit, bahwa produk biskuit penambahan tepung ubi jalar kuning dan daging ikan cakalang sudah memenuhi standar mutu SNI untuk kadar lemak dan kadar protein.Kata kunci: Biskuit,ubi jalar kuning, daging ikan cakalang lumat

Identification of yellowfin tuna (Thunnus albacares), mackerel tuna (Euthynnus affinis), and skipjack tuna (Katsuwonus pelamis) using deep learning

Yellowfin tuna (Thunnus albacares), mackerel tuna (Euthynnus affinis), and skipjack tuna (Katsuwonus pelamis) have important economic values for the capture fisheries in Indonesia. Activities of identifying these fish and other types of tuna have been done manually, which can lead to errors and ultimately affect statistics, stock estimates, or traceability. The aim of this research is to use deep learning methods in identifying three species of tuna, specifically yellowfin tuna, mackerel tuna, and skipjack tuna. YOLO’s newest model, YOLOv5, was used to identify the fish. The number of epochs that produces the optimum accuracy value for use in the YOLOv5 model is 400. The values for training loss, accuracy, precision, recall and F1-Score when the model is learning with a total of 400 epochs are 0.000253, 95%, 98.1%, 93.9%, and 96%. Based on these results, the three species of tuna can be identified with high accuracy.

Product Authentication Using Two Mitochondrial Markers Reveals Inconsistent Labeling and Substitution of Canned Tuna Products in the Taiwanese Market

Fish of the tribe Thunnini represent a significant proportion of the stock caught by the fishing industry, with many of these fishes being collectively called tuna. However, only certain species can be used legally as an ingredient in canned tuna products, depending on regional food regulations. In Taiwan, only Thunnus species or Katsuwonus pelamis can be used as canned tuna. Here, we authenticated 90 canned tuna products, including 25 cat food samples, by sequencing two mitochondrial regions, 16S rRNA (16S) and the control region (CR). BLAST analysis revealed that Sarda orientalis, Euthynnus affinis, Auxis rochei, and Auxis thazard are all used as substitutes for legitimate tuna products. We found that 63.33% of investigated samples are true canned tuna, i.e., contain Thunnus species or skipjack tuna. We advocate that the Taiwanese government publishes an official standardized list of fishes, especially so that scientific, Chinese and vernacular names can be assigned unambiguously based on a “one species-one name policy”, thereby clarifying which species can be used in seafood products such as tuna. Furthermore, we feel that the large-scale and long-term monitoring of canned tuna products is warranted to fully assess the extent of tuna product adulteration in Taiwan.

Population dynamic of skipjack (Katsuwonus pelamis) in Timor Sea, East Nusa Tenggara, Indonesia

Skipjack tuna is one of the potential fishery commodities in the waters of Timor, East Nusa Tenggara. This fish is exploited throughout the year without any management policies. This study aims to analyse population dynamic parameter. Length data were collected at the Oeba Fish Base from April to December 2020. Data analysis, size structure and age group of the Bhattacharya method, the L∞ and K values of the Ford and Walford method, total mortality by length catch converted curve, natural mortality by Pauly method, Y/R using the Beverton and Holt method. The results showed that the smallest fish was 27 cm FL, the largest was 71 cm FL, the dominant size is 55-58 cm FL and the average length was 48,68 ± 10,67 cm FL, L∞ 91.00 cm FL, and K 0.51 year1. The population consists of three age groups, the values of Z, M, F and E are 2.64 year1, 0.86 year1, 1.78 year1, and 0.68 year1 respectively. Current Y/R and optimal Y/R values are 0.036 and 0.060 grams recruit1 respectively. The conclusion, the high mortality of skipjack tuna is caused by fishing activities, and the high level of exploitation causes the recruitment process to be not optimal.

The Stock Status of Skipjack Tuna (Katsuwonus pelamis) in Tomini Bay and Its Surrounding Areas, Indonesia

Skipjack tuna (Katsuwonus pelamis) is an essential part of tuna, skipjack tuna, and mackerel tuna trades in Indonesia as the species is an economic commodity with export value. Tomini Bay is one of the areas in Indonesia with intensive skipjack tuna exploitation activities using purse seine fleets. Such a high fishing rate requires management efforts to maintain the species population’s sustainability. This study was conducted in April 2018–December 2019 at a fish landing site in Gorontalo City with a total sample of 8,833 skipjack tunas. The population dynamics, recruitment, and utilization rate were analyzed using FISAT II application and ELEFAN program. The results showed that the length at first capture (Lc) was 31.8 cmFL (in 2018) to 32.2 cmFL (in 2019) at around 1.3 year old. The fish recruitment occurred all year long, peaking in May at 16.12%. In addition, the utilization rate (E) of the species was 0.47, meaning that the species was already moderate to fully exploited. The suggested practical management efforts to maintain the population of the skipjack tunas in the area are to stop the fishing efforts from growing and control the size of the mesh for fishing.

A Study on Phyto-Chemical Analysis and Antibacterial Activity of Spices on Pathogenic Bacteria Isolated from Commercially Important Edible Marine Fishes, Euthynnus Affinis (Cantor), Katsuwonus Pelamis L. and Auxis Thazard (Lacepede) (Family Scombridae)

Ten bacterial species were isolated and monthly variations in their count were recorded from three edible tuna fishes. Phytochemical analysis and antibacterial activity of hexane, chloroform, methanol, and distilled water extracts of twelve common spices, against the isolated bacteria were evaluated. The study indicates that these pathogenic bacteria in all three tuna fish species cause various human health problems upon consumption.