• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.641-645
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• 2001

To utilize the by-products from whelk processing, whelk internal organ jeotgal was manufactured by adding pineapple and kiwifruit juices containing bromelain and actinidin, respectively. The protease activities of pineapple and kiwifruit juices were 52 and 248 unit/mL, respectively. 1 kg ground whelk internal organ was immersed to 12.5% salt concentration and then the 20, 50, or 100 mL of fruit juice were added in it. the quality of products fermented for up to 70 day at 1$0^{\circ}C$ was observed. Jeotgal wit pineapple juice showed lower pH and higher amino nitrogen content than with kiwifruit juice on 70 day of fermentation. the total nitrogen contents was the highest on 30 day of fermentation and stable thereafter. Although total numbers of microorganism were increased as fermentation progressed, there were no correlations among the juices or its adding amounts. It was thought that interactions between kinds of natural microflora and the proteases from fruit juices, and other constituents in jeotgal affected total nitrogen content of jeotgal and the growth rate of natural microorganisms. Of the all jeotgals in this study, no coliform was found It is suggested that the preparation of jeotgal with pineapple or kiwifruit juice is effective aspect of safety and quality.

• Korean Journal of Food Science and Technology
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• v.34 no.4
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• pp.570-576
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• 2002

For the utilization of the by-products of whelk processing, whelk internal organ with the addition of commercial proteolytic enzymes - Flavourzyme, Neutrase, Protease NP, Prozyme - were used to make jeotgal, Korean traditional salted and fermented seafood sauce. The products were prepared at salt concentration of 25% with enzyme contents 0.05 and 0.1%. The samples were stored at $10^{\circ}C$ and the chemical properties were evaluated for 6 months. The pH in all samples were decreased from near 6.8 in the beginning stage to 6.1-6.4 in the final stage of incubation. Amino nitrogen of jeotgal increased with enzyme concentration and showed maximum value, 646 mg%, at 0.1% of Flavourzyme. Total nitrogen content was increased till four months, but rapidly decreased after that. Protein degradations of whelk internal organ during maturation of jeotgals were investigated by SDS-PAGE. The patterns of degradation were different with added enzymes.

• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.78-83
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• 2001

To use the by-products of whelk processing, whelk internal organ with the addition of bromelain were used to make jeotgal, Korean traditional salted and fermented seafood sauce. The products were prepared at different salt concentrations of 10, 15 and 20% with various bromelain contents 0, 0.01, 0.1 and 0.5%. The samples were stored at $10^{\circ}C$ and the chemical and microbiological analyses were evaluated for four weeks. The initial pH (near 6.1) in all conditions decreased in the beginning stage of aging, then gradually increased until three weeks and finally decreased to $5.6{\sim}6.0$. The sample with lower salt concentration showed less pH change For two weeks. The samples treated with higher bromelain in 10% and 15% salt concentration showed higher pH values after 4 weeks compared to the nontreated control. Amino nitrogen in the samples increased at lower salt concentration and at higher bromelain content. The amino nitrogen showed maximum value, 780 mg%, at 10% salt and 0.5% bromelain treatment. Total nitrogen contents increased with aging periods, especially increased rapidly in high concentrations of bromelain treated samples at early stages of aging. The higher salt concentrations in the product decreased the total microbial number and lactic acid bacterial number.