Gelatin production from turkey (Meleagris gallopavo) skin as a new source: from waste to a sustainable food gelling agent.

BACKGROUND: Turkey skin, a byproduct of poultry processing, contains a significant amount of collagen that might be used to make non-mammal gelatin. However, gelatin production from turkey skin has not yet been investigated. The present study aimed to determine the optimum gelatin extraction conditions from turkey employing the central composite design and response surface methodologies. The independent factors such as temperature (50, 60, and 70 °C) and time (5, 7, and 9 h) were optimized for three response variables: yield, gel strength, and foam expansion (FE). RESULTS: With R2 values of 0.8576 for yield, 0.8386 for gel strength, and 0.9283 for foam expansion, linear, quadratic, and respective models were used. The yield, gel strength, and FE actual values were found to be 15.36%, 396.61 g, and 40%, respectively. The optimum extraction conditions were found to be 62.90 °C for 6.84 h. The foam stability, L, and b values were significantly impacted by temperature and extraction time (P < 0.05). CONCLUSION: The gel strength value of the gelatin extracted under optimal conditions was higher than that of commercial bovine. The findings of the present study showed that turkey skin is a suitable raw material for the manufacturing of gelatin. © 2023 Society of Chemical Industry.

A study on the structural, physicochemical, rheological and thermal properties of high hydrostatic pressurized pearl millet starch.

Starch in native form has limited application due to functional and physicochemical characteristics. To overcome these limitations, starch can be modified by non-thermal technologies such as high hydrostatic pressure (HHP). This study investigates high-pressure-induced gelatinization and the effect of this process on the structural, functional, morphological, pasting, thermal, physical and rheological properties of millet starch. The suspension of millet starch and water was pressurized at 200, 400 and 600 MPa for 10, 20 and 30 min to modify the starch in terms of structure, morphology, some physicochemical and rheological properties. Swelling strength and starch solubility decreased as a result of treatment with HHP. All treatments caused to increase in water holding capacity of the starch (from 0.66 % for native starch to 2.19 % for 600 MPa-30 min). Thermal analysis showed a decrease in gelatinization temperature and enthalpy of gelatinization and the pasting properties showed a decrease in the peak viscosity after HHP treatment. In addition, HHP treatment caused to increase in the hydration ability of starch by creating porosity and gaps in the granule surface and increasing the specific surface area. HHP application resulted in an increase in the peak time and pasting temperature and a decrease in breakdown and peak viscosities, final viscosity and setback viscosity in comparison with native starch of millet. The starch sample treated with 600 MPa for 30 min had the lowest syneresis and retrogradation ability. Increasing pressure and the time led to an increase in the elastic nature of the starch samples. According to the results, it is possible to increase usage area of starches in the food industry by improving its technological with HHP. This green physical technology can influence the quality parameters of starch, which can provide benefits for product machining and economic purposes.

Physicochemical, rheological, molecular, thermal and sensory evaluation of newly developed complementary infant (6-24 months old) foods prepared with quinoa (Chenopodium quinoa Willd.) flour.

The aim of the current work was to evaluate the physicochemical, rheological, molecular, thermal and sensory properties of complementary food (CF) formulations prepared with quinoa (Chenopodium quinoa Willd.) flour (QF). It was observed that QF addition significantly affected the physicochemical and rheological properties of CF formulations, resulting in higher protein and crude fiber, but lower total sugar contents and increased storage (G') and loss (G″) modulus values. The glass transition temperature decreased due to QF addition. The FTIR spectra revealed the presence of aromatic amino acids derived from QF. GC, GC-MS and GC-O analyses revealed the presence of 50 aroma and 23 aroma-active compounds, among which aldehydes, alcohols and ketones were the most prevalent group of compounds. The formulation with 8% QF received the highest sensory scores. QF could be used to improve the physicochemical, rheological, thermal and sensory properties of CF products.