Effects of Cooking Conditions on the Protein Quality of Chub Mackerel Scomber japonicus

Abstract

The effects of cooking method (grilling, frying, steaming, and microwaving) on the proximate composition and protein quality of chub mackerel Scomber japonicus treated with 2, 6, and 10% sodium chloride (NaCl) brine were investigated. Moisture content decreased in all cooked samples from 60.22% in the raw sample to 48.7% in the fried samples. Brine (10% NaCl) treatment recorded the highest moisture loss. All cooked samples showed a decrease in fat content, except fried samples. Protein content increased in all cooked samples, from 47.21% in the raw sample to 63.87% in the grilled sample. Brine treatment resulted in the highest degree of fat oxidation (thiobarbituric acid-reactive substances), which was highest in the fried samples and lowest in the microwaved samples. The trypsin inhibitor (TI) concentration was highest in the microwaved samples and lowest in the fried samples. In all samples, 6% salt treatment caused the lowest TI level and the highest in vitro protein digestibility. In vitro digestibility increased from 79.4% in the raw sample to 86.43% in the fried samples. The total essential amino acids of all cooked samples increased. Results suggested that grilling and steaming had beneficial effects on the protein quality of chub mackerel.

Effect of processing methods on nutritional and physico-chemical composition of fish: a review

“…21,22 It has health benefits, particularly to heart disease, blood pressures and a decreased risk of prostate cancer and Alzheimers's disease. 4,23…”

“…Oxidation of fat leads to both physical and chemical changes such as amino acid destruction, decrease in protein solubility due to polymerization, formation of amino acid derivatives and reactive carbonyl, changes in protein digestibility. 23,37…”

“…During heat processing, time and temperature are the main factors which can affect protein quality, as time and temperature increases denaturation of proteins is affected in large amount as well as there is loss of vitamins, minerals, some other essential amino acids and other beneficial nutrients. 14,23 Oduro et al, 23 investigated in their work that cooking fish via grilling, microwave, steaming and frying contributed in reducing of moisture and increasing protein content. From these heating conditions which caused fat extraction, hence decrease fat content is steaming, grilling and microwave.…”

Physicochemical Profiles of Chub Mackerel Scomber japonicus Bones as a Food Resource

“…Sulfur amino acids, such as cysteine and methionine, were not detected in CMB. Oduro et al (2011) reported amino acid profiles of mackerel muscles were rich in glutamic acid, aspartic acid, leucine and lysine, whereas contents of tryptophan, methionine and cysteine were low.…”

“…Chub mackerel is industrially processed by various protocols, such as roasting, salting and canning (Ju, 2011;Oduro et al, 2011). In the industrial processing of chub mackerel, the by-products, such as viscera, skin, bones, and head occupy about 50% of the total weight (Lee et al, 1986).…”