Impact of Enzymatic Hydrolysis and Microfluidization on the Techno-Functionality of Oat Bran in Suspension and Acid Milk Gel Models

Oat bran is a nutritionally rich ingredient, but it is underutilized in semi-moist and liquid foods due to technological issues such as high viscosity and sliminess. The aim of this work was to improve the technological properties of oat bran concentrate (OBC) in high-moisture food applications by enzymatic and mechanical treatments. OBC was hydrolyzed with β-glucanase (OBC-Hyd) and the water-soluble fraction (OBC-Sol) was separated. OBC, OBC-Hyd and OBC-Sol were further microfluidized at 5% dry matter content. Enzymatic treatment and microfluidization of OBC reduced the molecular weight (Mw) of β-glucan from 2748 kDa to 893 and 350 kDa, respectively, as well as the average particle size of OBC (3.4 and 35 times, respectively). Both treatments increased the extractability of the soluble compounds from the OBC samples (up to 80%) and affected their water retention capacity. OBC in suspension had very high viscosity (969 mPa·s) when heated, which decreased after both enzyme and microfluidization treatments. The colloidal stability of the OBC in suspension was improved, especially after microfluidization. The addition of OBC samples to acid milk gels decreased syneresis, improved the water holding capacity and softened the texture. The changes in the suspension and gel characteristics were linked with reduced β-glucan Mw and OBC particle size.

Approaches for Extracting Nanofibrillated Cellulose from Oat Bran and Its Emulsion Capacity and Stability

The pretreatment process is an essential step for nanofibrillated cellulose production as it enhances size reduction efficiency, reduces production cost, and decreases energy consumption. In this study, nanofibrillated cellulose (NFC) was prepared using various pretreatment processes, either chemical (i.e., acid, basic, and bleach) or hydrothermal (i.e., microwave and autoclave), followed by disintegration using high pressure homogenization from oat bran fibers. The obtained NFC were used as an emulsifier to prepare 10% oil-in-water emulsions. The emulsion containing chemically pretreated NFC exhibited the smallest oil droplet diameter (d32) at 3.76 μm, while those containing NFC using other pretreatments exhibited d32 values > 5 μm. The colors of the emulsions were mainly influenced by oil droplet size rather than the color of the fiber itself. Both NFC suspensions and NFC emulsions showed a storage modulus (G′) higher than the loss modulus (G″) without crossing over, indicating gel-like behavior. For emulsion stability, microwave pretreatment effectively minimized gravitational separation, and the creaming indices of all NFC-emulsions were lower than 6% for the entire storage period. In conclusion, chemical pretreatment was an effective method for nanofiber extraction with good emulsion capacity. However, the microwave with bleaching pretreatment was an alternative method for extracting nanofibers and needs further study to improve the efficiency.

Sources of Dietary Fiber Affect the SCFA Production and Absorption in the Hindgut of Growing Pigs

Effects of different dietary fiber (DF) sources on short-chain fatty acids (SCFA) production and absorption in the hindgut of growing pigs were studied by an in vivo–vitro (ileal cannulated pigs and fecal inoculum-based fermentation) method. Thirty-six cannulated pigs (body weight: 48.5 ± 2.1 kg) were randomly allocated to 6 treatments containing the same DF content (16.5%), with either wheat bran (WB), corn bran (CB), sugar beet pulp (SBP), oat bran (OB), soybean hulls (SH), or rice bran (RB) as DF sources. Pigs were allowed 15 days for diet adaptation, and then, fresh ileal digesta and feces were collected to determine SCFA concentration which was normalized for food dry matter intake (DMI) and the hindgut DF fermentability. Fecal microbiota was inoculated into the freeze-dried ileal digesta samples to predict the ability of SCFA production and absorption in the hindgut by in vitro fermentation. The SH group had the largest concentration of total SCFA and propionate in ileal digesta and fecal samples of growing pigs (p < 0.05). Nonetheless, the predicted acetate, total SCFA production, absorption in the SBP group were the highest (p < 0.01), but the lowest in the OB group (p < 0.01) among all groups. Even SBP and OB group had a similar ratio of soluble DF (SDF) to insoluble DF (IDF). The CB group had high determined ileal and fecal butyrate concentration but the lowest butyrate production and absorption in the hindgut (p < 0.01). Overall, the source of DF had a great impact on the hindgut SCFA production and absorption, and SBP fiber had a great potential to increase hindgut SCFA production and absorption.

A Meta-Analysis of Microbial Therapy Against Metabolic Syndrome: Evidence From Randomized Controlled Trials

Background and aims: Metabolic syndrome (MetS), accompanied with significant intestinal dysbiosis, causes a great public health burden to human society. Here, we carried out a meta-analysis to qualify randomized controlled trials (RCTs) and to systematically evaluate the effect of microbial therapy on MetS.Methods and results: Forty-two RCTs were eligible for this meta-analysis after searching the PubMed, Cochrane, and Embase databases. Pooled estimates demonstrated that treatment with microbial therapy significantly reduced the waist circumference (WC) (SMD = −0.26, 95% CI −0.49, −0.03), fasting blood glucose (FBG) (SMD = −0.35, 95% CI −0.52, −0.18), total cholesterol (TC) (SMD = −0.36, 95% CI −0.55, −0.17), low-density lipoprotein cholesterol (LDL-C) (SMD = −0.42, 95% CI −0.61, −0.22), and triacylglycerol (TG)(SMD = −0.38, 95% CI −0.55, −0.20), but increased the high-density lipoprotein cholesterol (HDL-C) (SMD = 0.28, 95% CI.03, 0.52). Sensitivity analysis indicated that after eliminating one study utilizing Bifidobacteriumlactis, results became statistically significant in diastolic blood pressure (DBP) (SMD = −0.24, 95% CI −0.41, −0.07) and in Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) (SMD = −0.28, 95% CI −0.54, −0.03), while the body mass index (BMI) showed significant difference after eliminating one study utilizing oat bran (SMD = −0.16, 95% CI −0.31, −0.01). There was still no significant effect in systolic blood pressure (SBP) and in hemoglobin A1c (HbA1c%).Conclusion: In patients with MetS, the conditioning with microbial therapy notably improves FBG, TC, TG, HDL-C, LDL-C, WC, BMI (except for the study using oat bran), HOMA-IR, and DBP (except for the Study using Bifidobacteriumlactis), however, with no effect in SBP and in HbA1c%.

Plantain based dough meal: nutritional property, antioxidant activity and dyslipidemia ameliorating potential in high-fat induced rats

Abstracts Background Dyslipidemia is an aberrant rise in blood lipids due to diet and lifestyle. It has implicated as the major risk factor for developing hypertension among other diseases. This study was designed to evaluate plantain based dough meal nutritional property, antioxidant activity and dyslipidemia ameliorating potential in high-fat induced rats. Methods The flour blends, i.e., PSC (Plantain 70%, Soycake 30%), PSR (Plantain 65%, Soycake 30%, Rice-bran 5%), PSO (Plantain 65%, Soycake 30%, Oat-bran 5%), PSRO (Plantain 60%, Soycake 30%, Rice-bran 5%, Oat-bran 5%) and controls (100% Plantain flour & Cerolina) were evaluated for chemical, antioxidants and antihyperlipidemia. Results Protein, fiber and energy composition varied from 2.2–4.97 g/100 g, 16.44–19.59 g/100 g and 369.7–385.5 kcal/100 g, respectively. Essential amino acid index and predicted-biological values of the foods ranged from 68.31–76.31% and 62.19–71.48%, respectively. Phenolic profiles (mg/g) were gallic acid (25.33–31.26), caffeic acid (2.75–4.61), ferulic acid (5.16–12.73), luteolin (16.31–23.60), kaempferol (21.51–30.64), quercetin (24.28–37.13), chlorogenic acid (42.25–59.78), myricetin (28.41–38.41), 3,5-dicaffeoylquinic acid (27.17–41.59) and 4, 5-dicaffeoylquinic acid (39.96–51.28). The antioxidant activity of PSRO on ABTS, DPPH, FRAP, Fe2+ chelation and OH free radicals was higher than other foods. Atherogenic index, coronary risk index and log (TG/HDL-conc.) of rats fed on experimental foods were lower than recommended values. Conclusion The study established that PSRO had higher antioxidant and anti-hyperlipidemia properties; hence, it may be suitable as a functional food.

Lignocellulose-Degrading Enzymes: A Biotechnology Platform for Ferulic Acid Production from Agro-Industrial Side Streams

Biorefining by enzymatic hydrolysis (EH) of lignocellulosic waste material due to low costs and affordability has received enormous interest amongst scientists as a potential strategy suitable for the production of bioactive ingredients and chemicals. In the present study, a sustainable and eco-friendly approach to the extraction of bound ferulic acid (FA) has been demonstrated using a single-step EH by a mixture of lignocellulose-degrading enzymes. For comparative purposes of the efficiency of EH, an online SFE-SFC-MS extraction and analysis approach was applied. The experimental results demonstrated up to 369.3 mg 100 g−1 FA released from rye bran after 48 h EH with Viscozyme L. The EH of wheat and oat bran with Viscoferm for 48 h resulted in 255.1 and 33.5 mg 100 g−1 of FA, respectively. The extraction of FA from bran matrix using the SFE-CO2-EtOH delivered up to 464.3 mg 100 g−1 of FA, though the extractability varied depending on the parameters used. The 10-fold and 30-fold scale-up experiments confirmed the applicability of EH as a bioprocessing method valid for industrial-scale. The highest yield of FA in both scale-up experiments was obtained from rye bran after 48 h of EH with Viscozyme L. In purified extracts, the absence of xylose, arabinose, and glucose as final degradation products of lignocellulose was proven by a HPLC-RID system. Up to 94.0% purity of FA was achieved by SPE using the polymeric reversed-phase Strata X column and 50% EtOH as eluent.