BACKGROUND: Poultry processing generates a large amount of industrial waste, which is rich in collagen content. This waste can be utilized for the extraction of valuable components such as gelatin, which can be used as an alternative to mammalian gelatin (porcine and bovine).
RESULTS: Gelatins were analyzed for their yield, proximate analysis, pH, color, viscosity, bloom strength, and texture profile analysis. The yield of broiler chicken feet gelatin (BCFG) was slightly higher (7.93%) as compared to native chicken feet gelatin (NCFG) (7.06%). The protein content was 85.92% and 82.53% for BCFG and NCFG. Both gelatin had moisture content in the standard range (< 15) as given by Gelatin Manufacturers of Europe (GME). Both gelatins showed higher bloom strength (326 g for NCFG and 203 g for BCFG) at 6.67% gelatin concentration, classified as high bloom. Fourier-transform infrared (FTIR) analysis showed amide I, amide A, amide B at 1636 cm-1, 3302 cm-1, 2945 cm-1 for NCFG and 1738 cm-1, 3292 cm-1, 2920 cm-1 for BCFG. At 6.67% gelatin concentration, hardness and cohesiveness values were also higher than commercial gelatin previously studied. The pH values for NCFG were 5.43 and BCFG was 5.31. Both NCFG and BCFG viscosities (4.43 and 3.85 cP) were in the optimum range of commercial gelatins (2-7 cP).
CONCLUSIONS: Hence, the present study concluded that both NCFG and BCFG have a huge potential to replace commercial mammalian gelatins (porcine and bovine) in the food industries. However further studies should be done to optimize the extraction process. © 2024 Society of Chemical Industry.

Background: The aim of this study was to determine the feasibility of the chicken foot model for surgical trainees interested in practising the designing, harvesting and inset of locoregional flaps of the hand. Methods: A descriptive study was performed to demonstrate the technical aspects of harvesting four locoregional flaps in a chicken foot model: fingertip volar V-Y advancement flap, four-flap and five-flap Z-plasty, cross-finger flap and first dorsal metacarpal artery (FDMA) flap. The study was performed in a surgical training laboratory on non-live chicken feet. No participants were involved in this study, apart from authors performing the descriptive techniques. Results: All flaps were successfully performed. Anatomical landmarks, soft tissue texture and flap harvest, as well as inset closely resembled clinical experience with patients. Maximal flap sizes were 12 × 9 mm for volar V-Y advancement, 5 mm limbs for Z-plasties, 22 × 15 mm for cross-finger flaps and 22 × 12 mm for FDMA flaps. The maximal webspace deepening with four-flap/five-flap Z-plasty was 20 mm and the FDMA pedicle length and diameter was 25 and 1 mm, respectively. Conclusions: Chicken feet can be effectively used as simulation models for hand surgical training with respect to gaining familiarity with the use of locoregional flaps of the hand. Further research requires testing for reliability and validity of the model on junior trainees.

In this study, the edible films from chicken feet (CF), ovine muscle fascia (MF), and bovine bone gelatin (Gel) were prepared and their characteristics were analyzed, and we also evaluated the sensory quality of raw and cooked hamburgers using the edible films. The quantities of the CF and MF hyaluronic acid were evaluated using colorimetry and spectrophotometry. The CF, MF, and Gel films were prepared by solvent casting method. Results indicated that the concentration of hyaluronic acid in CF (124.11 ppm) was greater than MF (101.11 ppm). The antioxidative property of the CF film (18.47%) was greater than the Gel (1.88%) and MF (Undetectable) film. The CF film was more resistant to water vapor permeability (2.75 × 10-9 g/m.s.pa) than the MF (1.57 × 10-8 g/m.s.pa) and Gel (1.5 × 10-7 g/m.s.pa) films. The Gel film had more appropriate mechanical properties than CF and MF films. The films kept burgers patties independent from one another and prevented them from sticking and freezing together. MF and CF films were able to promote the organoleptic properties of raw and cooked hamburgers in taste and texture.

In this study, edible films from chicken feet extract (CF), ovine muscle fascia extract (MF), and bovine bone gelatin powder (Gel) were prepared and their characteristics were analyzed. We also used the films as separators of burger cuts and evaluated the organoleptic characteristics of cooked burgers. Hyaluronic acid quantities of CF and MF were measured using colorimetric and spectrophotometry. Results indicated that the concentration of hyaluronic acid in CF (124.11 ppm) was greater than MF (101.11 ppm). The antioxidative property of the CF film (18.47%) was greater than the Gel (1.88%) and MF (Undetectable) films. The CF film was more resistant to water vapor permeability (2.75 × 10-9 g/m.s.pa) than the MF (1.57 × 10-8 g/m.s.pa) and Gel (1.5 × 10-7 g/m.s.pa) films. The Gel film had more appropriate mechanical properties than CF and MF films. The films kept burgers patties independent from one another and prevented them from sticking and freezing together. MF and CF films were able to promote the organoleptic properties of cooked burgers in taste and texture.

With the increasing global population, it has become necessary to explore new alternative food sources to meet the increasing demand. However, these alternatives sources should not only be nutritive and suitable for large scale production at low cost, but also present good sensory characteristics. Therefore, this situation has influenced some industries to develop new food sources with competitive advantages, which require continuous innovation by generating and utilising new technologies and tools to create opportunities for new products, services, and industrial processes. Thus, this study aimed to optimise the production of gelatin-base gels from chicken feet by response surface methodology (RSM) and facilitate its sensorial classification by Kohonen\'s self-organising maps (SOM). Herein, a 22 experimental design was developed by varying sugar and powdered collagen contents to obtain grape flavoured gelatin from chicken feet. The colour, flavour, aroma, and texture attributes of gelatines were evaluated by consumers according to a hedonic scale of 1-9 points. Least squares method was used to develop models relating the gelatin attributes with the sugar content and collagen mass, and their sensorial qualities were analysed and classified using the SOM algorithm. Results showed that all gelatin samples had an average above six hedonic points, implying that they had good consumer acceptance and can be marketed. Furthermore, gelatin D, with 3.65-3.80% (w/w) powdered collagen and 26.5-28.6% (w/w) sugar, was determined as the best. Thus, the SOM algorithm proved to be a useful computational tool for comparing sensory samples and identifying the best gelatin product.

In this research, products with high quality were obtained from natural sources. The sensorial qualities, chemical characterization, and physical properties of gelatin extracted from chicken feet were compared with commercial gelatins. The extraction process was performed using acetic acid on a concentration ranging from 0.318% to 3.682%, processing time between 1.0 h and 8.4 h and extraction temperature between 43.3 °C and 76.8 °C. After the end of each assay, the yield was measured. Results showed that, under the best conditions, the collagen extraction yield was above 8%, and comprised 78.525 g/100 g of protein. Collagen analyzed by ICP-MS was composed of 99.44% of macro-minerals that are of great importance to human health. ATR-FTIR analysis showed that approximately 70.90% of the total protein from chicken feet is collagen, whereas, in commercial gelatin, only 30.31% is collagen. When comparing chicken gelatin with commercial gelatin, most sensory attributes were similar and chicken gelatin gained acceptance by more than 80% of the consumers. Additionally, the collagen films obtained from chicken feet and swine showed water absorption, odors, and texture characteristics similar to commercial material, such as latex and celofane. Consequently, due to its similarity to human skin, it is possible to apply it as a biocurative.

In the European Union (EU), about five tons of poultry by-product tissues are produced every year. Due to their high collagen content, they represent a significant raw material source for gelatine production. The aim of the paper was the biotechnological preparation of gelatine from chicken feet. The influence of selected process factors on the gelatine yield, gel strength, viscosity, and ash of gelatine was observed; a two-level factor design of experiments with three variable process factors (enzyme addition, enzyme treatment time, and gelatine extraction time) was applied. After grinding and separating soluble proteins and fat, the purified raw material was treated in water at pH 7.5 with the addition of endoprotease at 23 °C and after thorough washing with water at 80 °C, gelatine was extracted. By the suitable choice of process conditions, gelatine with high gel strength (220-320 bloom), low ash content (<2.0%) and viscosity of 3.5-7.3 mPa·s can be prepared. The extraction efficiency was 18-38%. The presented technology is innovative mainly by the enzymatic processing of the source raw material, which is economically, technologically, and environmentally beneficial for manufacturers. Chicken gelatines are a suitable alternative to gelatines made from mammals or fish, and can be used in many food, pharmaceutical, and biomedical applications.

Chicken feet have become an important commodity in the international market, representing a significant portion of poultry products exported by countries such as Brazil and the USA. However, the presence of pododermatitis in the footpad is an important barrier to exportation, since importing countries do not accept injured feet or allow the use of automatic equipments to remove the affected tissue. The objective of this research was to evaluate the impact of using an automatic equipment to remove injuries of pododermatitis on histological and microbiological traits of broiler feet processed according to commercial practices. A total of 240 broiler feet obtained from a commercial processing plant was visually classified according to the degree of pododermatitis and distributed in a 4 × 2 factorial arrangement, totalizing eight treatments with 30 replications. Factors were feet classification (1 to 4) and injury removal (yes or no). Feet were sampled for microbiological and histological analysis before and after the mechanical removal of pododermatitis injuries by an automatic machine that promoted footpad epidermal scarification. No significant interaction between feet classification and injury removal was detected for any of the analyzed variables. Also, no significant effect of feet classification was detected on aerobic plate counts, total coliforms and Escherichia coli. Feet inflammation score tended to increase (P = 0.06) according to the downgrading of feet classification, but the mechanical removal of pododermatitis injuries reduced feet inflammation score (P < 0.01), total coliform counts (P = 0.01), and E. coli (P = 0.01) independently of feet classification. Together, these results demonstrate the efficacy of the automatic equipment in removing both the inflammatory tissue and its associated microbiota in broiler feet affected by pododermatitis. Therefore, in addition to the already authorized use of blades, the use of automatic equipments for epidermal scarification in the processing of broiler feet deserves further consideration by the regulatory agencies.