Research Article - Central European Journal of Experimental Biology ( 2019) Volume 7, Issue 1
Color, odor, taste, texture and overall acceptable score of cooked Mullet (fried and grilled) fish steaks during the storage period at -18°C were evaluated. The colors score of fried and grilled steaks of mullet showed good qualities as indicated by 9.1 ± 0.028 and 8.7 ± 0.034, respectively. The initial score values for taste and odor of fried and grilled Mullet samples were as high as (9 ± 0.288 and 9.5 ± 0.057) and (9 ± 0.115 and 9.5 ± 0.288), respectively. The texture score of fried and grilled which were as high as 9.3 ± 0.057 and 9.2 ± 0.115, respectively. The scores in all cooked samples slightly decreased during frozen storage from zero to 180 days either in fried or grilled Mullet fish samples. The fried and grilled cooked Mullet fish samples prepared from the pre-frozen raw fish showed good qualities. They maintained the high acceptability during frozen storage for 180 days.
Mullet fish, Frying, Grilling, Sensory evaluation, Frozen storage.
In Egypt, the total quantity of catch fish recorded 1,706,273 tones, while the total quantity of Exports and Imports of fish were 47,812 and 311,068 tonnes, respectively. Annual average share per capita of fish was 21.64 kg . Mullets are one of the most important fish in Egyptian fisheries . The most popular fish cooking methods are frying, grilling, boiled and baked. These methods affect in enhancing sensory evaluation parameters, hygiene quality and improve the digestibility . Some chemical and physical reactions take place during cooking of fish such as improves the nutritional value of protein due to denaturation that increases its digestibility . The grilling method has recently become more popular. Grilling is a mean of cooking by radiant heat from below and is different from broiling which means cooking by radiant heat from above. In the foodservice industry, the grill has become synonymous with griddle. Both terms refer to the equipment that has a flat and solid heated surface to cook, such as hamburgers, steaks, chops, and cutlets. This equipment allows cooking with or without the addition of fat . Deep Fat Frying (DFF) is a major cooking method and is considered to be one of the oldest methods of food preparation. It is a cooking method of immersing foods in hot oil at a temperature above the boiling point of water. The oil temperature usually varies from 130°C to 200°C. During frying, there are many chemical reactions take place such as browning, gelatinization and denaturation due to the elevated temperature of the product . Freezing is considered, all over the world, as one of the best methods for long-term preservation of perishable foods. Freezing reduces chemical reactions as well as microbial activity in the tissue, thus extending the shelf life of the product. Next, to fresh foods, frozen items attract high consumer acceptance in terms of sensory parameters including appearance, texture, and flavor, as well as nutritional value . Indices of freshness or spoilage of seafood have been extensively studied, and it is generally accepted that there is a poor correlation between remaining shelf-life, as determined by sensory methods, and aerobic viable counts . All these microscopic changes, caused by bacteria, autolytic enzymes or other chemical reactions, are translated into changes in the sensory attributes of fish or seafood. Sensory changes are those perceived with the senses, i.e. appearance, odor, texture and taste. If knowledge on the eating quality of chilled fish during storage is required, a sensory assessment of the fish, cooked under controlled conditions, can be conducted .
Therefore, the overall objective of this study was to determine the changes in sensory evaluation scores of fried and grilled Mullet fish steaks during frozen storage at -18°C for a six months period.
Ten kilograms of fresh Mullets fish (Mugil cephalous) were obtained from one of the fishermen in Wadi El-Rayan Lake, Fayoum Governorate in February 2016. They had been transported in ICE-BOX to the laboratory of Fish Processing Technology, National Institute of Oceanography and Fisheries (NIOF), Fayoum Governorate, Egypt. In the laboratory, whole fish were immediately beheaded, gutted and cut into steaks then washed gently with tap water. Steaks samples were divided into four groups. One of them was cooked by frying and grilling methods in the same day of the acquisition of the fish, corresponding to 0 days. The other samples were packed in polyethylene bags with oxygen permeability, stored at -18˚C for six months in the domestic freezer, and removed for analysis after 60, 120 and 180 days to cook.
Fried and grilled Mullet fish steaks samples were tested for color, odor, taste, texture and overall acceptability immediately after processing and periodically during refrigeration and frozen storage by ten panelists chosen from the staff members of the shakshouka fish research station. Fish products were evaluated according to the method of  using the following numerical system:
• Excellent 8.6-10
• Very good 7.6-8.5
• Good 6.6-7.5
• Accepted 5.0-6.5
• Poor 4-4.9
• Very poor 0-3.9
Sensory evaluation data were analyzed statistically using SPSS 16.0 for windows (SPSS Inc., Chicago, USA). Least Significant Difference test (LSD) at (P ≤ 0.05) and Standard Error (Mean ± SE) were calculated.
Fried and grilled Mullet fish steaks prepared from the pre-frozen raw fish showed good qualities. They maintained the high acceptability during frozen storage for 180 days. Meanwhile, for some extend, it was observed that the grilled Mullet fish samples were more liked by the panelists than fried samples during storage period.