Mammalian gelatin is extensively utilized in the food industry because of its physicochemical properties. However, its usage is restricted and essentially prohibited for religious people. Fish gelatin is a promising alternative with no religious and social restrictions. The desirable properties of fish gelatin can be significantly improved by various methods, such as the addition of active compounds, enzymes, and natural crosslinking agents (e.g., plant phenolics and genipin), and nonthermal physical treatments (e.g., ionizing radiation and high pressure). The aim of this study was to explore whether the properties of fish gelatin (gel strength, melting or gelling temperature, odor, viscosity, sensory properties, film-forming ability, etc.) could be improved to make it comparable to mammalian gelatin. The structure and properties of gelatins obtained from mammalian and fish sources are summarized. Moreover, the modification methods used to ameliorate the properties of fish gelatin, including rheological (gelling temperature from 13-19°C to 23-25°C), physicochemical (gel strengths from ∼200 to 250 g), and thermal properties (melting points from ∼25 to 30°C), are comprehensively discussed. The relevant literature reviewed and the technological advancements in the industry can propel the development of fish gelatin as a potential alternative to mammalian gelatin, thereby expanding its competitive market share with increasing utility.

Repurposing fish waste into gelatin as a potential alternative for mammalian sources: A review.

The flame-retardant modification of rice straw fibers (RSFs) was carried out to solve the technical problem of poor fire-proof performance of RSFs. The physical and mechanical properties and thermal insulation properties of rice straw fiber cement-based composites (RSFCC) at high temperatures were characterized. The results show that the three flame retardants affected the chemical structure of RSFs. The thermal stability and flame retardancy of flame-retardant RSFs were significantly higher than that of non-flame-retardant RSFs. The crystallinity of several groups of modified RSFs increased in varying degrees compared to untreated fibers. The mass-loss rate of RSFCC increased with the increase of temperatures. The strength and thermal conductivity of RSFCC decreased with the rise of temperatures. The strength and thermal conductivity of the composite flame-retardant modified fiber RSFCC at high temperatures were significantly higher than those of the non-flame retardant modified fiber or the single flame retardant modified fiber RSFCC.

Effect of flame-retardant rice straw fibers on properties of fiber cement-based composites at high temperatures

In this paper gelatin beads reinforced with natural hemp hurd have been produced as pH sensitive devices for the release of eugenol, as green pesticide. The composites beads, with a mean diameter of about 1 mm, were obtained by polymer droplet gelation in sunflower oil. Thermal properties were evaluated showing no noticeable difference after the introduction of hemp hurd. Barrier properties demonstrated an improvement of hydrophobization. The introduction of 5% w/w of hemp hurd led to a reduction of sorption coefficient of about 85% compared to unloaded gelatin beads. Besides, the diffusion coefficient decreased, introducing 5% w/w of hemp hurd, from 8.91 × 10−7 to 0.77 × 10−7 cm2/s. Swelling and dissolution phenomena of gelatin beads were studied as function of pH. The swelling of gelatin beads raised as pH increased up to 2.3 g/g, 9.1 g/g and 27.33 g/g at pH 3, 7 and 12, respectively. The dissolution rate changed from 0.034 at pH 3 to 0.077 h−1 at pH 12. Release kinetics of eugenol at different pH conditions were studied. The released eugenol after 24 h is 98%, 91%, 81 and 63% w/w (pH 3), 87%, 62%, 37 and 32 wt% (pH 7) and 81%, 68%, 60 and 52 wt% (pH 12) for unloaded gelatin beads and gelatin beads with 1%, 3 and 5% of hemp hurd, respectively. The eugenol release behavior was demonstrated to be highly sensitive to the pH release medium, which allows to tune such devices as green pesticide release systems in soils with different level of acidity/basicity.

/pdf/gelatin-beads-hemp-hurd-as-ph-sensitive-devices-for-delivery-210dxwnd0s.pdf

Gelatin Beads/Hemp Hurd as pH Sensitive Devices for Delivery of Eugenol as Green Pesticide

http://www.cell.com/article/S2405844022034636/pdf

Properties of flame-retardant leaf fiber cement-based composites at high temperatures

The main objective of this work was to estimate the usefulness of response surface methodology (RSM) and genetic algorithm (GA) in modeling and predicting the strength of jute/poly(lactic acid) (PLA) composite laminates. Firstly, the impact of the hot water treatment on the thermal, molecular structure, and morphological characterizations as well as kinetic analysis of jute fibers were performed by Thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM). The FTIR results showed that the hot water treatments reduced the content of lignin, hemicellulose, and impurities of the fibers. Hot water treated fibers exhibited higher thermal stabilities compared with untreated fibers as shown with TGA results. The SEM results showed effect contact surface area improved after the hot water treatment, leading to better mechanical properties of bio-composites. Secondly, the influences of the ply orientation, plies and fiber content on the tensile strength and flexural strength of the hot water treated fibers composites were evaluated by RSM. RSM with the Box Behnken Design was utilized to establish the quadratic models of two objectives in response to input parameters. Analysis of variance (ANOVA) was used to determine percentage contribution of various parameters on two quality objectives. According to the ANOVA results, ply orientation had the most important impact on tensile strength while the ply orientation-fiber content interaction had the most important impact on flexural strength. Finally, multi-objective optimization was carried out to maximize tensile strength and flexural strength using the desirability function and GA. The optimized results both showed an acceptable relative error between experimental and optimized values. 

Investigation and prediction of mechanical properties of hot water treated jute/poly(lactic acid) composite laminates using response surface methodology and genetic algorithm

The focus of this work was to analyze the influence of leaf treatments on mechanical, physical and chemical properties and thermal stability of the gelatin/lotus leaf composites. Lotus leaves were treated with drinking water at 95 °C for 5 min. The gelatin/untreated lotus leaf (referred to as GUL) and the gelatin/hot water treated lotus leaf (referred to as GHL) composites have been prepared by the compression molding technique. The composites have been investigated by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TAG), Scanning electron microscopy (SEM). Effect of the lotus leaf hand lay-up fiber orientation was studied for longitudinal, transverse and random orientation of the fibers. The tensile strength of gelatin/lotus leaf composites were influenced by the orientation of the fibers. It was found that longitudinal orientation delivered higher mechanical properties than that of the transverse and random orientation whether untreated or treated. The hot water modification of the lotus leaf was employed to improve the interfacial adhesion of the composites in order to improve the tensile properties. By using TGA analysis data and Ozawa-Flynn-Wall (OFW) method, the thermal stability and degradation temperature of the lotus leaves treated with hot water were higher than those of untreated leaves. In addition, the properties of the novel bio-composites were potential in further development of biodegradable packaging materials.

Chunxia He

Papers

Impact of Hot Water Treated Lotus Leaves on Interfacial and Physico-Mechanical of Gelatin/Lotus Leaf Composites