Influence of collagen and some proteins on gel properties of jellyfish gelatin

Abstract

Marine gelatin is one of the food proteins used in food and non-food products, offering desirable functionalities such as gelling, thickening, and binding. Jellyfish has been chosen for this gelatin research, in view of the benefits of its main collagen protein and lower fat content, which may reduce the amounts of chemicals used in the preparative steps of gelatin production. To date, the lack of identified proteins in gelatin has limited the understanding of differentiating intrinsic factors quantitatively and qualitatively affecting gel properties. No comparison has been made between marine gelatin of fish and that of jellyfish, regarding protein type and distribution differences. Therefore, the study aimed at characterizing jellyfish gelatin extracted from by-products, that are i.e., pieces that have broken off during the grading and cleaning step of salted jellyfish processing. Different pretreatment by hydrochloric acid (HCl) concentrations (0.1 and 0.2 M) and hot water extraction time (12 and 24 h) were studied as factors in jellyfish gelatin extraction. The resultant jellyfish gelatin with the highest gel strength (JFG1), as well as two commercial gelatins of fish gelatin (FG) and bovine gelatin (BG), were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The results show that the jellyfish gelatin (JFG1) extracted with 0.1 M HCl at 60°C for 12 h delivered a maximum gel strength of 323.74 g, which is lower than for FG and BG, exhibiting 640.65 and 540.06 g, respectively. The gelling and melting temperatures of JFG1 were 7.1°C and 20.5°C, displaying a cold set gel and unstable gel at room temperature, whereas the gelling and melting temperatures of FG and BG were 17.4°C, 21.3°C, and 27.5°C, 32.7°C, respectively. Proteomic analysis shows that 29 proteins, of which 10 are types of collagen proteins and 19 are non-collagen proteins, are common to all BG, FG, and JFG1, and that JFG1 is missing 3 other collagen proteins (collagen alpha-2 (XI chain), collagen alpha-2 (I chain), and collagen alpha-2 (IV chain), that are important to gel networks. Thus, the lack of these 3 collagen types influences the inferior gel properties of jellyfish gelatin.

Effect Collagen Concentration Tilapia Scales on the Quality of Burn Ointment

“…Based on analysis of variance (ANOVA) shows that Fhit>Ftab means that the addition of fish scale collagen extract has a significant effect on the dispersion value. This is in accordance with the statement of [16] collagen has thickening properties. Collagen mixed into ointment preparations as an active substance can affect the ointment base itself, so that the spreadability is lower.…”

Influence of extraction times on physical and functional properties of gelatin from salted jellyfish by-products

“…For gelatin extraction, jellyfish by-products gelatin was prepared according to Lueyot et al [11] and Charoenchokpanich et al [12] with a slight modification. Firstly, the desalted by-products (1 kg) were agitated at 150 rpm and 4 o C for 2 h with 0.5 M sodium hydroxide (NaOH) solution (1:3, w/v) in a shaking incubator (WIS-20R, WiseCube, Korea).…”

“…However, the gel strength of commercial fish gelatin (306.11 g) was lower than that of the JFG48 sample. Previous research has found that jellyfish by-products gelatin has lower gel strength due to differences in collagen type, the alpha and beta chain ratio in the gelatin, and the gelatin peptides of the alpha chain [11]. The lowest gel strength of jellyfish (Lobonema smithii) gelatin was 108.36 g [15].…”

“…Marine gelatin is mainly produced from by-products to decrease food waste and the functional qualities of marine gelatin. Several researchers have reported gelatin extracted from marine by-products such as cold-water fish (chum salmon [6]), warm-water fish (cobia [7], pangasius catfish [8], and tilapia [9][10]), and jellyfish [11][12].…”

“…The low price of salted jellyfish by-products but rich in collagen protein with minimal fat content [14][15][16][17][18] have potentially been a source for gelatin extraction. The attempts to improve jellyfish gelatin by varying hydrochloric acid (HCl) pretreatment conditions (concentration and time), extraction temperature, and extraction time [11][12][15][16] have been reported. Charoenchokpanich et al [12] reported that the condition of 2 h HCl pretreatment at 25 o C and 3 h water extraction at 60 o C was insufficient for the jellyfish gelatin process and delivered the low gel strength of 214.47 g. Research on the functional properties of jellyfish gelatin produced from salted jellyfish byproducts has been limited.…”