Recent advances on the role of process variables affecting gelatin yield and characteristics with special reference to enzymatic extraction: A review

Effect of tuna skin gelatin-based coating enriched with seaweed extracts on the quality of tuna fillets during storage at 4 °C

“…Besides this, it can be also an indicator of gelatin quality. Ash content value (1.36 ± 0.07 %; Table 2) was consistent with the literature, being the maximum recommended for gelatin of 2.6 % (Ahmad et al, 2017;Haddar et al, 2012). The lower value of ash content obtained suggests that the extracted gelatin was of high quality.…”

“…In this work, and as a consequence of low FG protein, the gel strength value was low (148.2 ± 5.00 g; Table 2). A comparable range of gel strength values between 656 -151 (g) were reported by Ahmad et al (2017) on FG extracted from skin of Asian seabass (Lates calcarife), dover sole (Solea vulgaris) and unicorn leatherjacket (Alutherus monoceros) at temperatures between 43°C and 70°C. Cho et al (2005) also verified lower strength values for tuna skin FG extracted at 54°C, with an increase of 24 % in strength values when extractions were performed at 40°C.…”

“…FG colour parameters are presented in Table 2. According to Ahmad et al (2017), gelatins extracted at 45°C (mid temperatures) are expected to have low a* and b* values and high values of L*. In this work, low L* values and high a* values were obtained for the extracted gelatin.…”

“…In this work, low L* values and high a* values were obtained for the extracted gelatin. This indicated that the colour of extracted gelatin was less brightness but more redness compared to gelatins obtained by Ahmad et al (2017).…”

“…Associated with collagen thermal denaturation, is the use of pretreatments, with either acid or alkali, allowing the swelling of collagen to increase gelatin extraction. Depending on the final objective or application, it is possible to adjust gelatin properties using different pH and temperature ranges, and time applied during both pre-treatments and the extraction process (Ahmad et al, 2017). Another important topic is the possibility to incorporate natural bioactive compounds, adding functionality to coatings.…”