الفهرس 
INTRODUCTION
REVIEW OF LITERATUREOnly 14 pages are availabe for public view
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Abstract
The present study was determined 2 items (Quality criteria, proximate composition, public health hazards of commercial canned tuna and experimental study for improvement of quality of home-manufactured Albacore tuna).
Part І: Quality criteria, proximate composition, and public health hazards of commercial canned tuna. A total of 90 samples from canned tuna of all commercial brands in each brand three types (chunks, solid and crumbled) were randomly collected during the years of 2020 and 2021 from different supermarkets in Assiut city, Egypt. All samples of canned tuna were collected within their validity date.
The results of sensory evaluation showed that all the examined canned tuna were accepted organoleptically.
The data revealed that pH values of the examined chunks tuna, solid tuna and crumbled tuna samples with mean values of 6.15 ± 0.04, 6.13 ± 0.03, and 6.32 ± 0.03, respectively, were in compatible with Egyptian Standards (ES, 2013).
Regarding moisture content of the examined canned tuna samples, the results showed that the values in chunks tuna samples with a mean value of 66.42 ± 0.41, while in solid tuna samples with a mean value of 66.19 ± 0.29. In case of crumbled tuna samples, with mean values of 66.12 ± 0.62 was recorded.
It is evident from the results outlined that the protein content of the examined chunks tuna samples with a mean value of 25.29 ± 0.14. However, in solid tuna samples protein content with a mean value of 26.40 ± 0.18. Besides, the mean value of protein content of the examined crumbled tuna samples was 24.00 ± 0.16.
The total results cited that the mean fat content (%) values of examined chunks tuna, solid tuna, and crumbled tuna samples were 5.97 ± 0.47; 5.09 ± 0.29 and 10.91 ± 0.70, respectively.
As for, the free fatty acids content (%), data revealed that the mean value of the examined chunks tuna samples was 2.68 ± 0.05. As for, solid tuna samples the previously mentioned value was 2.12 ± 0.03. Regarding crumbled tuna samples, the mean value was 3.05 ± 0.05. The achieved results declared that fifteen fatty acids in tuna fish flesh were identified in the present study.
from the summarized results, it is evident that the calcium content (mg/100gm) of chunks tuna and solid tuna samples with mean values of 129.17 ± 15.77 and 123.40 ± 20.44, respectively. For crumbled tuna samples the mean calcium value was 121.18 ± 15.83. The achieved results noted that the mean values of phosphorus content (mg/100gm) of the examined chunks and solid tuna samples were 358.21 ± 27.29 and 240.37 ± 14.62. On the other hand, the phosphorus content mean value of the examined crumbled tuna samples was 113.19 ± 7.61.
The obtained results showed that the energy value (Kcal/100gm) of chunks tuna, solid tuna and crumbled tuna samples with mean values of 163.55 ± 4.11, 162.00 ± 3.33 and 204.28 ± 6.32, respectively. The achieved results declared that the mean values of cholesterol content (mg/100gm) of the examined chunks tuna and solid tuna samples were 39.91 ± 0.62 and 38.82 ± 0.74. On the other hand, the cholesterol mean value of the examined crumbled tuna samples was 40.09 ± 0.71.
Chunks tuna showed the highest mean value of moisture content, while solid tuna showed the highest mean values of protein, ash and carbohydrate. Crumbled tuna was the highest in pH, fat, energy and cholesterol. On the other hand, the lowest mean values for energy and cholesterol were detected in solid tuna, while, the lowest mean values for moisture, protein and ash were observed in crumbled tuna samples. As well, solid tuna showed the lowest mean values of pH and fat content; meanwhile, chunks tuna showed the lowest mean values of carbohydrate percentage.
The present study was done to estimate the concentrations of three heavy metals (mercury, lead and cadmium) in canned tuna fish.
The current study resulted chunks tuna samples that 7 samples with a percentage (70%) from 10 examined samples were contained mercury in different concentration, for solid tuna were 6 samples with a percentage (60%) from 10 samples examined while crumbled tuna that 9 samples with a percentage (90%) from 10 examined samples were contained mercury in different concentrations. from the obtained data these 13 samples from examined samples with a percentage (59.09%) were above the maximum limit of mercury in fish (0.5) ppm according to Food and Agriculture Organization (FAO/WHO, 1992) and Egyptian standard specifications (ES, 2010).
The current study resulted chunks tuna samples that 7 samples with a percentage (70%) from 10 examined samples were contained lead in different concentration, for solid tuna were 5 samples with a percentage (50%) from 10 samples examined while crumbled tuna that 8 samples with a percentage (80%) from 10 examined samples were contained lead in different concentrations. from the obtained data these 10 samples from examined samples with a percentage (50%) were above the maximum limit of lead in fish (0.3) ppm according to Egyptian standard specifications (ES, 2010), but for Food and Agriculture Organization (FAO/WHO, 1992) there were 17 samples with a percentage (85%) as represented which above the maximum limit of lead in fish (0.1) ppm.
The current study resulted chunks tuna samples that 4 samples with a percentage (40%) from 10 examined samples were contained cadmium in different concentration, for solid tuna were 3 samples with a percentage (30%) from 10 samples examined while crumbled tuna that 6 samples with a percentage (60%) from 10 examined samples were contained cadmium in different concentrations. from the obtained data these 7 samples from examined samples with a percentage (53.85%) were above the maximum limit of cadmium in fish (0.05) ppm according to Food and Agriculture Organization (FAO/WHO, 2011).
According to the ingredients labels of examined tuna cans, only meat (skeletal muscles) of fish must be observed within the cans. However, our observation detected unauthorized tissues as fish tissue, frozen muscles, and plant tissue. Also, inedible parts such as degenerated and infected muscles were detected.
Therefore, we recommend consuming solid tuna in diet because it is the highest in the value of protein and calories from protein and essential fatty acids because it contains the highest level of approximately 39.2% of polyunsaturated fatty acids and is considered the lowest in the value of fat and cholesterol content, and the lowest average values of energy. Also, solid tuna is the lowest level in total saturated fatty acids (23.5%) as Palmitic (C16:0) (16.8%). Followed by, the consumption of chunks tuna, as it is the highest in calcium and phosphorous values. Also, avoid consuming crumbled tuna because it has the highest values of pH, fat, energy and cholesterol. The lowest average values of moisture, protein and ash were observed in the crumbled tuna samples, and it contained the highest percentage of toxic heavy metals (mercury, lead and cadmium). It also contained cartilage, bones, parts of the central nervous system, skin, liver, plant tissues and parasites destroyed by heat or freezing in histological examination at a higher rate compared to other types of tuna.
Part П: Experimental study for improvement of quality of home-manufactured Albacore tuna (Thunnus alalunga) by marinading and using natural additives and spices, and effect of chilling on nutritive value and health hazard of this tuna, and measuring deterioration criteria as pH, TVN and TBA. Our results of TVN value were less than 40 mg N/100g is considered acceptable as evidence of freshness so were compatible with Egyptian Standards (ES, 2013).
from the summarized results, it is evident that the entire home-manufactured Albacore tuna (Thunnus alalunga) were accepted organoleptically using 9- point hedonic scale. Chemical analysis of home-manufactured Albacore tuna as well as public health importance was done.
The present results proved that home-manufactured Albacore tuna (Thunnus alalunga) were with high nutritional values and lower health risks, and no differences between three methods used in the manufacture.