Search Results (26)

Bulgurs with increased resistant starch (RS) contents were produced from high-amylose wheat and Svevo wheat samples by pullulanase treatment and autoclaving–cooling cycles. Cooking properties, color, texture, phenolic content, antioxidant capacity, in vitro glycemic index, and RS contents of bulgurs were examined. RS contents of bulgurs obtained by enzyme application and autoclaving–cooling cycles were 3-folds higher than those of the control bulgurs and reached a level of 9.47%. The GI value of the bulgur produced from high-amylose wheat by pullulanase treatment and autoclaving–cooling cycles was quite low (52.11), and hence it can be classified as a low-GI food. Pullulanase application and autoclaving–cooling cycles had significant effects on textural properties of bulgurs. Phenolic content and antioxidant capacity values were found to be the highest in bulgurs obtained by enzyme application and autoclaving–cooling cycles. These results can be used to improve the health benefits of bulgur by increasing its RS content and decreasing its GI value. Full article

Inoculating legumes with nitrogen-fixing bacteria, such as Bradyrhizobium, can significantly reduce reliance on synthetic nitrogen fertilizers. To optimize this process, a suitable rhizobial strain must be carefully selected and formulated. This study aimed to develop a biopolymer blend formulation for Bradyrhizobium pachyrhizi strain BR 3262. From four commercial starches and two carboxymethylcelluloses (CMC), we developed CMC/starch blends compatibilized or not with MgO at concentrations from 0.1% to 1.0% and subjected them to autoclaving for either 30 or 60 min. The resulting inoculants were stored for 168 days. Generally, blends compatibilized with 1.0% MgO exhibited a significant decrease in cell numbers, likely due to the observed pH values of approximately 10. The best performance was observed for CMC-I/starch B blends autoclaved for 60 min, and CMC-II/starch C blends autoclaved for 30 min, both compatibilized with 0.3% MgO. These blends maintained a cell viability of 10⁸ CFU mL⁻¹ for approximately 130 days at room temperature. Blend optimization depends on the selection of specific interactions and quantities of each component in order to achieve a given functionality; in the conditions of this study, the capacity to maintain Bradyrhizobium cell viability for at least four months. Full article

Starch digestibility and the content of resistant starch (RS) play a crucial role in human health, particularly in relation to glycemic responses, insulin sensitivity, fat oxidation, and satiety. This study investigates the impact of processing methods on potato starch digestibility and RS content, focusing on two modification techniques: autoclaving and high hydrostatic pressure (HHP), followed by retrogradation at different temperatures. The research employs a comprehensive approach to characterize structural changes in starch samples using X-ray diffraction (XRD), attenuated total reflectance–Fourier transform infrared (ATR-FTIR) spectroscopy, and scanning electron microscopy (SEM). In turn, semi-dynamic in vitro digestion experiments based on the INFOGEST protocol were conducted to assess starch digestibility, while RS content was evaluated through enzymatic digestion of the non-RS fraction. SEM, XRD, and FTIR measurements reveal thermal processing appreciably affected starch architectures while HHP had a marginal effect. Further, the FTIR 1045/1022R ratio was found to be correlated with RS content measurements while reducing rapidly digestible starch (RDS). The findings led to the stipulation that thermal processing facilitates amylose leaching and granular disruption. In turn, retrogradation enabled the deposition of the amylose onto the disrupted structures which delineated their subsequent liability to enzymatic digestion. Conversely, HHP had minimal effects on granular architectures and amylose leaching. Overall, this research provides valuable insights for processing starch-based food products with the goal of increasing RS content, which may have significant implications for the food industry and nutritional science. Full article

The quest for natural preservation systems is on the rise due to health hazards associated with synthetic preservatives. The current study explores a significant research gap by investigating the antifungal potential of Eucalyptus citriodora essential oil (EO) and modified potato peel starch (M-PPS)-based coatings to control the fungal contamination in peanut kernels, providing a sustainable food preservation system. Potato peel starch was extracted by water steeping and modified by autoclaving. E. citriodora EO was extracted from leaves by steam distillation and chemically characterized using a gas chromatography mass spectrometer (GC-MS). The antifungal potential of EO was evaluated by radial growth inhibition assay (RGI). EO completely inhibited the growths of Penicillium griseofulvum and Aspergillus niger at a concentration of 3.125 µL/mL, which was marked as the minimum inhibition concentration (MIC). EO induced cellular leakage from fungal cells, and hyphae became pitted, indicating the strong antifungal potential of EO. EO (2 ×MIC)-treated rice seeds showed complete inhibition of A. niger after 7 days of incubation, and in the control treatments, all the rice seeds were contaminated (100% contamination index). M-PPS and EO-based coatings controlled the growth of P. griseofulvum in peanut kernels. After incubation for 7 days, control treatments were fully contaminated with fungal growth, whereas the M-PPS and EO-based coatings restricted the growth of fungi in peanut kernels. The M-PPS and EO-based preservation system can be used for the preservation of perishable food products. Full article

The transformation of hypoglycin A (HGA), hypoglycin B (HGB), and methylene cyclopropyl glycine (MCPrG) in ruminal fluid batch cultures was investigated, and the effect of these toxins on the batch culture microorganisms using microbial metabolites was measured. An experiment was conducted using ovine ruminal fluid batch cultures and the ANKOM RF Gas Production System over four runs, each with an incubation period of 48 h. The fermenters contained 200 mg of (i) a substrate mixture (80% cellulose, 20% starch; CSM), (ii) CSM and 1.5 mL of a solution of pure toxins (a mixture of 500 ng/mL HGA and MCPrG each; PCM), or (iii) CSM and 100 mg sycamore maple seeds (SMS). Each fermenter contained 30 mL of inoculum (ruminal fluid and buffer, 1:2 v/v). For control, autoclaved ruminal fluid was incubated with CSM, PCM, and SMS, respectively. Samples were taken from the liquid phase of the fermenters and analyzed using liquid chromatography–tandem mass spectrometry (LC/MS-MS) for sycamore maple toxins and metabolites. Microbial activity was assessed using gas production, short chain fatty acids, and NH₃ concentration. Additionally, pH and redox potentials were measured. In PCM, HGA and MCPrG concentrations rapidly decreased (p < 0.05), and were not measurable anymore after a 24 h incubation period. In SMS, the initial concentrations were 4.7 ± 1.4 µg/mL HGA, 19.9 ± 5.41 µg/mL HGB, and 1.2 ± 0.33 µg/mL MCPrG. In SMS, HGA increased in 24 h, coincidently to a decrease in HGB concentration (p < 0.05). We modeled a rapid conversion of HGB to HGA, accompanied by progressive HGA transformation. The concentration of MCPrG was constant until 4 h and decreased afterwards (p < 0.05). In SMS incubations, HGA and MCPrG concentrations of 5.6 ± 1.5 and 0.32 ± 0.090 µg/mL remained after 48 h, respectively. The HGB to HGA conversion and transformation of HGA and MCPrG also occurred in autoclaved ruminal fluid. Gas production and microbial metabolite concentrations were higher in SMS compared to CSM and PCM (p < 0.05), as the seeds were used as an additional substrate by the batch culture microorganisms. Full article

The processing properties of resistant starch (RS) and its digestion remain unclear, despite the widespread use of autoclaving combined with debranching in its preparation. In this study, the physicochemical, rheological and digestibility properties of autoclaving modified starch (ACB), autoclaving–pullulanase modified starch (ACPB) and native black Tartary buckwheat starch (NB) were compared and investigated. The molecular weight and polydispersity index of modified starch was in the range of 0.15 × 10⁴~1.90 × 10⁴ KDa and 1.88~2.82, respectively. In addition, the SEM results showed that both modifications influenced the morphological characteristics of the NB particles, and their particles tended to be larger in size. Autoclaving and its combination with pullulanase significantly increased the short-range ordered degree, resistant starch yield and water- and oil-absorption capacities, and decreased the syneresis properties with repeated freezing/thawing cycles. Moreover, rheological analysis showed that both ACB and ACPB exhibited shear-thinning behavior and lower gel elasticity as revealed by the power law model and steady-state scan. The degradation of starch chains weakened the interaction of starch molecular chains and thus changed the gel network structure. The in vitro digestion experiments demonstrated that ACB and ACPB exhibited greater resistance to enzymatic digestion compared to the control, NB. Notably, the addition of pullulanase inhibited the hydrolysis of the ACB samples, and ACPB showed greater resistance against enzymatic hydrolysis. This study reveals the effects of autoclaving combined with debranching on the processing properties and functional characteristics of black Tartary buckwheat starch. Full article

Defatted rice bran (DRB) is the by-product of rice bran oil extraction and presents approximately 66% carbohydrates and 15% proteins, a composition with the potential to integrate biorefinery systems. This study aimed to investigate the feasibility of residual fractions from ultrasound-assisted protein extraction from DRB as sources of carbohydrates in bioprocesses. First, DRB was exposed to protein extraction in an alkaline medium assisted by ultrasound. The residual fractions, including the precipitate from the extraction process (P1) and the supernatant from protein precipitation (S2), were combined and autoclaved to gelatinize the starch. Enzyme activity tests showed that a temperature of 70 °C was optimal for the simultaneous application of α-amylase and amyloglucosidase (AMG). To study enzymatic hydrolysis, a Full Factorial Design (FFD) 2² was employed, with α-amylase and AMG concentrations ranging from 0.12 to 0.18 mL∙L⁻¹ and a substrate concentration (P1/S2 ratio) between 30 and 70 g∙L⁻¹, resulting in a maximum of 18 g∙L⁻¹ of reducing sugars (RS). Fermentation assays with Saccharomyces cerevisiae demonstrated that the hydrolysate of the residual fractions was effective for ethanol production (8.84 g∙L⁻¹ of ethanol; Y_P/S: 0.614 g_ethanol∙g_RS⁻¹; η: 120.24%), achieving results comparable to control media (with sucrose as the substrate), indicating its potential for application in bioprocesses. These outcomes highlight a promising technological approach for utilizing DRB in integrated biorefineries. Full article

Poly(propylene carbonate-co-phthalate) (PPC-P) is an amorphous copolymer of aliphatic polycarbonate and aromatic polyester; it possesses good biodegradability, superior mechanical performances, high thermal properties, and excellent affinity with CO₂. Hence, we fabricate PPC-P foams in an autoclave by using subcritical CO₂ as a physical blowing agent. Both saturation pressure and foaming temperature affect the foaming behaviors of PPC-P, including CO₂ adsorption and desorption performance, foaming ratio, cell size, porosity, cell density, and nucleation density, which are investigated in this research. Moreover, the low-cost PPC-P/nano-CaCO₃ and PPC-P/starch composites are prepared and foamed using the same procedure. The obtained PPC-P-based foams show ultra-high expansion ratio and refined microcellular structures simultaneously. Besides, nano-CaCO₃ can effectively improve PPC-P’s rheological properties and foamability. In addition, the introduction of starch into PPC-P can lead to a large number of open cells. Beyond all doubt, this work can certainly provide both a kind of new biodegradable PPC-P-based foam materials and an economic methodology to make biodegradable plastic foams. These foams are potentially applicable in the packaging, transportation, and food industry. Full article

The potential of PulY103A (a moderate amylopullulanase originating from Bacillus megaterium) for resistant starch production under moderate conditions (40 °C; a pH of 6.5) was investigated. PulY103A was much more suitable for pea resistant starch production with a high growth rate of 3.63. The pea resistant starch (PSpa) produced with PulY103A had lower levels of swelling power and solubility and a better level of thermostability than native pea starch (PSn) and autoclaved PS (PSa). The starch crystallinity pattern was B + V, which indicated that the PSpa belonged to RS types III + V. In addition, PSpa was used for breadmaking. The results showed that the bread quality was not significantly influenced compared to the control group when the content of PSpa was under 10% (p > 0.05). The bread supplemented with 10% PSpa had a significantly increased TDF content compared to that of the control (p < 0.05). Moreover, the in vitro mineral bioavailability of the bread sample was influenced gently compared to other dietary fibers, and the bread sample changed from a high-glycemic-index (GI) food to a medium-GI food corresponding to white bread at the same concentration of PSpa. These results indicated that PSpa is a good candidate for the production of dietary foods. Full article

Kepok banana can be used as a functional food ingredient. Efforts were made to improve the functional properties of Kepok banana starch by modifying it by autoclaving cooling. Modified banana starch can be combined with other flours in food products. The study objective was to determine the effect of modified Kepok banana starch substitution on the fat, dietary fiber, and resistant starch content of cooky products. The experimental design involved four treatments, which varied the percentage of modified banana starch substitution as follows: 0% (P0), 25% (P1), 50% (P2), and 75% (P3). Substitution with modified Kepok banana starch increased the fat, dietary fiber, and resistant starch content. Full article

Fusarium is a genus that mostly consists of plant pathogenic fungi which are able to produce a broad range of toxic secondary metabolites. In this study, we focus on a type A trichothecene-producing isolate (15-39) of Fusarium sporotrichioides from Lower Austria. We assessed the secondary metabolite profile and optimized the toxin production conditions on autoclaved rice and found that in addition to large amounts of T-2 and HT-2 toxins, this strain was able to produce HT-2-glucoside. The optimal conditions for the production of T-2 toxin, HT-2 toxin, and HT-2-glucoside on autoclaved rice were incubation at 12 °C under constant light for four weeks, darkness at 30 °C for two weeks, and constant light for three weeks at 20 °C, respectively. The HT-2-glucoside was purified, and the structure elucidation by NMR revealed a mixture of two alpha-glucosides, presumably HT-2-3-O-alpha-glucoside and HT-2-4-O-alpha-glucoside. The efforts to separate the two compounds by HPLC were unsuccessful. No hydrolysis was observed with two the alpha-glucosidases or with human salivary amylase and Saccharomyces cerevisiae maltase. We propose that the two HT-2-alpha-glucosides are not formed by a glucosyltransferase as they are in plants, but by a trans-glycosylating alpha-glucosidase expressed by the fungus on the starch-containing rice medium. Full article

A pellet-forming as-catalyst, CuO/Al₂O₃, was prepared by the precipitation–tablet molding method and characterized by the Brunner–Emmet–Teller (BET), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) techniques and TEM. The characterization results showed that the formed CuO/Al₂O₃ was in situ reduced to Cu/Al₂O₃ and Cu₂O/ Al₂O₃ catalysts in the reaction system. The catalytic performance of catalyzing hydrogenation starch into glucose was investigated in an autoclave over CuO/Al₂O₃. The yield of glucose reached 83.16% at a temperature of 160 °C, a pressure of 1.8 MPa, a 100 g starch solution of 15 wt%, a catalyst dosage of 2.25%, a reaction time of 4 h, and a rotational speed of 630 r/min. The reusability of the catalyst was evaluated, and the glucose yield did not decrease obviously even after being reused for five consecutive cycles. Starch was converted into glucose through the synergistic action of Cu⁺ and Cu⁰ catalysis. This work is expected to provide valuable insights into the design of catalysts and the hydrogenation process for efficient starch hydrogenation. Full article

Potato peel waste (PPW) was utilized as a bio-template for the production of valuable compounds such as reducing sugars (RS), total sugar (TS) and total phenolic compounds (TPC). Two methods of alkali treatments, i.e., chemical (NaOH) and thermochemical (NaOH assisted with autoclaving) processes, were employed for the deconstruction of PPW. Response surface methodology (RSM) was used to study the effects of alkali concentration (0.6–1.0 w/v), substrate concentration (5–15 g) and time (4–8 h) on the extraction of RS, TS and TP from PPW. The application of alkali plus steam treatment in Box-Behnken design (BBD) with three levels yielded the optimum releases of RS, TS and TP as 7.163, 28.971 and 4.064 mg/mL, respectively, corresponding to 10% substrate loading, in 0.6% NaOH for 8 h. However, the alkali treatment reported optimum extractions of RS, TS and TP as 4.061, 17.432 and 2.993 mg/mL, respectively. The thermochemical pretreatment was proven a beneficial process as it led to higher productions of TP. FTIR and SEM were used to analyze the deterioration levels of the substrate. The present work was used to explore the sustainable management of PPW, which is a highly neglected substrate bioresource but is excessively dumped in open environment, raising environmental concerns. The cost-effective methods for the breakdown of PPW starch into fermentable sugars might be utilized to extract valuable compounds. Full article

Interactions between food components have a positive impact in the field of food science. In this study, the effects of tea polyphenol on the structural and physicochemical properties of Chinese yam starch using autoclave-assisted pullulanase treatment were investigated. X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, rapid visco analysis, differential scanning calorimetry, and the 3,5-dinitrosalicylic acid method were applied in this study. The results showed that the Chinese yam starch–tea polyphenol complex formed a structural domain with higher thermal stability along with lower pasting viscosities than native starch. The in vitro digestibility of Chinese yam starch decreased with the addition of the tea polyphenol, and the amount of resistant starch content in the complex was 56.25 ± 1.37%, significantly higher than that of native starch (p < 0.05). In addition, the complex showed a B+V-type crystalline structure, which confirmed that the interaction modes between the starch and tea polyphenol include hydrogen bonding and hydrophobic interactions. Moreover, the appearance of an irregular sponge network structure of the complex further supported the interactions between the starch and tea polyphenol. This study provides a theoretical basis for the development of functional foods using Chinese yam starch. Full article

Resistant starch appears to have promising effects on hypertension, cardiovascular and enteric illness. The influence of resistant starch on intestinal physiological function has drawn great attention. In this study, we first analyzed the physicochemical characteristics, including the crystalline properties, amylose content, and anti-digestibility among different types of buckwheat-resistant starch. The influence of resistant starch on the physiological functions of the mouse intestinal system, contained defecation, and intestinal microbes were also evaluated. The results showed that the crystalline mold of buckwheat-resistant starch changed from A to B + V after acid hydrolysis treatment (AHT) and autoclaving enzymatic debranching treatment (AEDT). The amylose content in AEDT was higher than in AHT and raw buckwheat. Moreover, the anti-digestibility of AEDT was also stronger than that in AHT and raw buckwheat. The buckwheat-resistant starch can promote bowel intestinal tract movement. The quantity of intestinal microbe was regulated by buckwheat-resistant starch. Our research demonstrates an effective preparation method for improving the quality of buckwheat-resistant starch and found that buckwheat-resistant starch has the role of adjusting the distribution of the intestinal flora and maintaining the health of the body. Full article