Resistant starchtype III (RS3) possess various beneficial physiological effects as well as functionality in food containing resistant starch (RS). In this study, RS3 is produced from breadfruit (Artocarpus altilis) starch using different processing conditions involving disruption of starch granules, enzymatic debranching of starch polymer, starch retrogradation and drying. Then, the morphology and size of the starch granules were observed using scanning electron microscope (SEM). A sample with the highest RS content (54.59%), denoted as P8 was produced when the breadfruit starch was suspended in distilled water, gelatinised by heating at 90°C for 30 minutes, followed by starch debranching with 20 New Pullulanase Unit Novo (NPUN) enzyme per g starch at 60°C for 24 hours. The suspension was then autoclaved at 121°C for 1 hour and cold stored at 4°C for 24 hours. Further treatment of P8 sample with 0.5 M HCl acid at 60°C for 24 hours, produced HCl-breadfruit RS3 with 57.86% of RS content. It was observed that hydrolysis of breadfruit RS3 sample with HCl produced smoother starch granules with more crystalline region and proportionally increased the RS content when compared to other treated sample. This study revealed that different processing conditions were significantly influenced the percentage of yield and properties of RS type III produced from breadfruit starch.

Biodegradable films containing different concentrations of duck feet gelatin (DFG) (2.0, 2.5, 3.0, and 3.5%) were produced, and their mechanical and physicochemical properties were measured and compared to those of biodegradable films made from commercial bovine gelatin (CBG). Gel strength of DFG (306.96 g) was significantly higher than that of CBG (216.78 g). Elongation at break (EAB), thickness, and water vapour permeability of DFG films significantly increased as the concentration of gelatin increased. Films with DFG concentration of 3.5% had the EAB value 33.00, compare to CBG with EAB value 25.56%. DFG films exhibit significantly lower water solubility compared to CBG films. Water solubility of films with DFG concentration of 3.5% is 32.37%, meanwhile for CBG is 48.74%. Both of the gelatin films prepared from DFG and CBG were transparent, as indicated by the high L*, ranging from 94.64 to 96.01 for DFG and 95.54 to 96.06 for CBG sources. These results indicate that DFG has great potential for future application as a source material for production of gelatin-based biodegradable films.

HCl-breadfruit resistant starch type III (HCl-BFRS3) is a type of resistant starch (RS) produced from breadfruit (Artocarpus altilis). Generally, RS is the non-digestible starch fraction that resists digestion in the gastrointestinal tract, and is completely or partially fermented in the colon which gives it beneficial physiological effects as a potential prebiotic. The present work assessed the fermentation properties of HCl-BFRS3 produced by local underutilised food crops. HCl-BFRS3 with 57.86% of RS content was analsyed for its fermentation properties. In vitro fermentability of HCl-BFRS3 with pure cultures of lactic acid bacteria, LAB (Lactobacillus plantarum ATCC 13649 and L. brevis ATCC 8287), was studied. Their growth patterns, pH changes, and prebiotic activity score (PAS) along with four other different carbohydrate sources (glucose, inulin, fibersol-2, and breadfruit starch) and a control sample against Escherichia coli ATCC 11775 was evaluated after 72 h of fermentation. It was found that HCl-BFRS3 selectively supported the growth of both lactobacilli and E. coli ATCC 11775, in the range of 6.21 to 9.20 log10 CFU/mL. HCl-BFRS3 also decreased the pH from the fermentation by L. plantarum ATCC 13649 and L. brevis ATCC 8287 after 24 h. The highest PAS was obtained by L. plantarum ATCC 13649 grown on HCl-BFRS3 (+1.69) as compared to inulin and fibersol-2. In conclusion, HCl-BFRS3 could be exploited as a prebiotic that benefits human health. Nevertheless, further assessment on the suitability of HCl-BFRS3 as a prebiotic material needs to be carried out.

Duck skin is the by-product of duck meat production, and it is a readily available source of gelatin that may serve as an alternative to gelatin made from pigs and cows. In this study, the physicochemical properties of Peking duck skin gelatin were assessed. Duck skin gelatin was extracted using acid pretreatment (ADS) or mixed alkaline-acid pretreatment (ALDS). The extraction yield of ALDS (1.95%) was significantly higher than that of ADS (1.33%), and the recovery of protein of ALDS was 46.47% compared to 43.77% for ADS. The bloom value of ADS (364.10 g) was significantly higher than that of ALDS (205.13 g) and commercial type B bovine gelatin (BG, 224.20 g). The high bloom value of ADS and medium bloom value of ALDS mean that they can be used in many food applications. The hydroxyproline content of ADS (13.84 g/100 g) also was significantly higher than that of ALDS (10.25 g/100 g) and BG (12.87 g/100 g). The pH of ADS and BG (5.31 and 4.90, respectively) did not differ significantly, whereas the pH of ALDS was 8.34. Viscosity values of ADS and ADLS were 13.51 and 12.35 mPas, respectively, which were significantly higher than that of BG (3.62 mPas). Overall, these results show that duck skin is a potential raw material for gelatin production, as it has a high bloom value and is readily available in Malaysia.

Malaysia is one of the main producers of duck meat globally with increasing demands. Increasing in duck production will also increase the number of duck by-products such as skin, feet and bones. Pekin duck (Anas platyrhyncos domestica) is one of the famous duck breeds. Gelatin that was extracted from Pekin duck feet has shown a potential raw material for the production of bioactive peptide that can involve in various functions of the organism physiologically for example antioxidant effects. Pekin Duck feet gelatin was hydrolyzed by using five commercial enzymes (Alcalase, Esperase, Flavourzyme, Neutrase and Protamex) to identify radical scavenging potencies of derived bioactive peptides. All the five enzymes were studied under three different enzyme-substrate ratio (1:10, 1:15, 1:20) with every enzyme optimum pH and temperature. Scavenging activities studied included DPPH radical scavenging activity and ABTS radical scavenging activity. In DPPH radical scavenging activity, all the five enzymes showed the highest percentage of radical scavenging activity at (1:20) enzyme-substrate ratio condition. Among the five enzymes studied, gelatin hydrolyzed with Protamex showed the highest activity (54.83%), followed by Alcalase (53.12%), Esperase (49.81%), Flavourzyme (49.32%) and lastly Neutrase (47.49%) at sample concentration 4.5 mg/ml. The half-maximal inhibitory concentration (IC50) value of the bioactive peptide for ABTS radical scavenging activity was measured. Alcalase has produced the duck feet gelatin hydrolysate that has the lowest IC50 value against ABTS radical scavenging activity with value (0.45%) followed by Esperase (0.54%), Neutrase (0.57%), Protamex (0.60%) and lastly Flavourzyme (0.74%).