On the other hand, the urea-soluble fraction (S3) increased progressively up to 24 h with a subsequent decrease during the prolonged fermentation time. This suggested that hydrophobic interactions were particularly important during the initial stage of fermentation reported that surface hydrophobicity of natural actomyosin (NAM) increased with reduction of pH. The involvement of hydrophobic interactions in gelation process of heat-induced fish mince has been described by some researchers