Moving towards Gel for Fish Feeding: Focus on Functional Properties and Its Acceptance

Abstract

To resurrect and establish a low-impact aquaculture practice, gel-based feed applications hold promise. Gel feed is viscoelastic, nutrient-dense, hard, flexible, and appealing, and can be moulded into appealing shapes to ensure rapid acceptance by fish. The purpose of this research is to create a suitable gel feed using various gelling agents and to evaluate its properties and acceptance by a model fish, Pethia conchonius (rosy barb). Three gelling agents, viz. starch, calcium lactate and pectin, were included at 2%, 5%, and 8% in a fish-muscle-based diet. The physical properties of gel feed were standardized using texture profile analysis, sinking velocity, water and gel stability, water holding capacity, proximate composition, and colour. The lowest levels of nutrient leaching protein (0.57 ± 0.15%) and lipid (14.3 ± 14.30%) were observed up to 24 h in the underwater column. The highest score for overall physical and acceptance characteristics was noted for the 5% calcium lactate-based gel feed. Furthermore, a 20-day acceptance feeding experiment was conducted using 5% calcium lactate to examine its suitability as fish feed. The results indicate a better acceptability (3.55 ± 0.19%) and water stability (−2.5 ± 2.5%) of the gel feed compared to the control, with an improvement in nutrient losses. Overall, the study provides an insight into the application of gel-based diets for ornamental fish rearing, besides ensuring an efficient nutrient uptake and minimal leaching to establish a clean aquatic environment.

Recent Insights about the Role of Gels in Organic Photonics and Electronics

“…There are numerous examples of gel applications found, for example, in sensors [3][4][5], actuators [6][7][8], tissue engineering [9,10], drug-delivery systems [11][12][13], and drug crystallization [14][15][16]. In addition to well-developed applications, other emerging ones can be found such as: 3D/4D printing [17,18], food and related applications [19][20][21], energy storage [22,23], agriculture applications [24,25], or even applications in the cosmetic industry [26][27][28].…”