To lower the retrogradation and digestibility of waxy corn starch for different food applications,a novel thermostable GtfC type 4,6-α-glucanotransferase without N-and C-terminals(GsGtfC)from Geobacillus sp.12AMOR1 w...To lower the retrogradation and digestibility of waxy corn starch for different food applications,a novel thermostable GtfC type 4,6-α-glucanotransferase without N-and C-terminals(GsGtfC)from Geobacillus sp.12AMOR1 was used.Waxy corn starch of 50 g/L was incubated with GsGtfC of 40-100 U/g substrate at 65℃and pH 5.5 for 1 h.Its molecular weight,iodine affinity,XRD crystallinity,and FTIR ratio of heights of bands at 1047 and 1022 cm^(-1) decreased,but ratio of DP<6 to DP≥25 branches and degree of branching increased.GsGtfC cleavedα-1,4-glycosidic bonds and inducedα-1,6-branching points to produce reuteran-likes polymers,which is different from Exiguobacterium sibiricum GtfC enzyme cleavingα-1,4-glycosidic bonds and synthesizing consecutiveα-1,6-glycosidic bonds to produce isomalto/malto-oligosaccharides.GsGtfC modified waxy corn starch had significantly lower DSC retrogradation enthalpies during the storage at 4℃for 3-14 days and significantly lower released glucose during the incubation with mammalian mucosalα-glucosidase at 37℃for 10-360 min.GsGtfC at 100 U/g substrate increased slowly digestible portion from 11.07%to 24.11%.展开更多
With the escalating environmental impact of petrochemical-based packaging,the development of biodegradable alternatives from agricultural waste has become imperative.This study describes the fabrication and optimizati...With the escalating environmental impact of petrochemical-based packaging,the development of biodegradable alternatives from agricultural waste has become imperative.This study describes the fabrication and optimization of a sustainable,bio-based cushioning material derived from a corn starch foam matrix and corn husk fibers via compression molding.The investigation of starch ratios revealed that 100%normal corn starch(NCS)provided superior expansion and structural integrity compared to waxy starch,which exhibited significant cell wall collapse under SEM analysis.To enhance formability,xanthan gum(XG)was incorporated as a stabilizer;a 1.0%(w/w)concentration was found to be the morphological inflection point,yielding a refined closed-cell structure and a bulk density of 0.43 g/cm^(3).The stabilized matrix was reinforced with 2.0%to 6.0%(w/w)corn husk fibers pre-treated with tetraethoxy silane(TEOS)to improve interfacial adhesion.The addition of 6.0%fibers significantly augmented the material’s energy absorption capacity,achieving a peak impact strength of 1.87±0.50 kJ/m^(2)and a compressive strength of 0.56 N/mm^(2).These results demonstrate that the optimized agricultural waste-derived composite effectively surpasses the load-bearing capabilities of traditional commercial foams,offering a viable,eco-friendly solution for high-load protective packaging.展开更多
基金This work was sponsored in part by National Natural Science Foundation of China(NSFC-31671801,31371749)the key R&D program(21ZGN38)from Changchun science and technology bureau,the special project of industrial independent innovation capability(2020C036-7)from Jilin provincial development and reform commission+1 种基金the science and technology research planning project(JJKH20220609KJ)from Jilin provincial department of educationthe scholar climbing project(ZKP202006 and ZKP202016)from Changchun University.
文摘To lower the retrogradation and digestibility of waxy corn starch for different food applications,a novel thermostable GtfC type 4,6-α-glucanotransferase without N-and C-terminals(GsGtfC)from Geobacillus sp.12AMOR1 was used.Waxy corn starch of 50 g/L was incubated with GsGtfC of 40-100 U/g substrate at 65℃and pH 5.5 for 1 h.Its molecular weight,iodine affinity,XRD crystallinity,and FTIR ratio of heights of bands at 1047 and 1022 cm^(-1) decreased,but ratio of DP<6 to DP≥25 branches and degree of branching increased.GsGtfC cleavedα-1,4-glycosidic bonds and inducedα-1,6-branching points to produce reuteran-likes polymers,which is different from Exiguobacterium sibiricum GtfC enzyme cleavingα-1,4-glycosidic bonds and synthesizing consecutiveα-1,6-glycosidic bonds to produce isomalto/malto-oligosaccharides.GsGtfC modified waxy corn starch had significantly lower DSC retrogradation enthalpies during the storage at 4℃for 3-14 days and significantly lower released glucose during the incubation with mammalian mucosalα-glucosidase at 37℃for 10-360 min.GsGtfC at 100 U/g substrate increased slowly digestible portion from 11.07%to 24.11%.
基金supported by King Mongkut’s University of Technology Thonburi(KMUTT),Thailand Science Research and Innovation(TSRI),and National Science,Research and Innovation Fund(NSRF)Fiscal year 2026 Grant number FRB690020/0164.
文摘With the escalating environmental impact of petrochemical-based packaging,the development of biodegradable alternatives from agricultural waste has become imperative.This study describes the fabrication and optimization of a sustainable,bio-based cushioning material derived from a corn starch foam matrix and corn husk fibers via compression molding.The investigation of starch ratios revealed that 100%normal corn starch(NCS)provided superior expansion and structural integrity compared to waxy starch,which exhibited significant cell wall collapse under SEM analysis.To enhance formability,xanthan gum(XG)was incorporated as a stabilizer;a 1.0%(w/w)concentration was found to be the morphological inflection point,yielding a refined closed-cell structure and a bulk density of 0.43 g/cm^(3).The stabilized matrix was reinforced with 2.0%to 6.0%(w/w)corn husk fibers pre-treated with tetraethoxy silane(TEOS)to improve interfacial adhesion.The addition of 6.0%fibers significantly augmented the material’s energy absorption capacity,achieving a peak impact strength of 1.87±0.50 kJ/m^(2)and a compressive strength of 0.56 N/mm^(2).These results demonstrate that the optimized agricultural waste-derived composite effectively surpasses the load-bearing capabilities of traditional commercial foams,offering a viable,eco-friendly solution for high-load protective packaging.
