Walnuts and Vegetable Oils Containing Oleic Acid Differentially Affect the Gut Microbiota and Associations with Cardiovascular Risk Factors: Follow-up of a Randomized, Controlled, Feeding Trial in Adults at Risk for Cardiovascular Disease.

Background: It is unclear whether the favorable effects of walnuts on the gut microbiota are attributable to the fatty acids, including α-linolenic acid (ALA), and/or the bioactive compounds and fiber. Objective: This study examined between-diet gut bacterial differences in individuals at increased cardiovascular risk following diets that replace SFAs with walnuts or vegetable oils. Methods: Forty-two adults at cardiovascular risk were included in a randomized, crossover, controlled-feeding trial that provided a 2-wk standard Western diet (SWD) run-in and three 6-wk isocaloric study diets: a diet containing whole walnuts (WD; 57–99 g/d walnuts; 2.7% ALA), a fatty acid–matched diet devoid of walnuts (walnut fatty acid–matched diet; WFMD; 2.6% ALA), and a diet replacing ALA with oleic acid without walnuts (oleic acid replaces ALA diet; ORAD; 0.4% ALA). Fecal samples were collected following the run-in and study diets to assess gut microbiota with 16S rRNA sequencing and Qiime2 for amplicon sequence variant picking. Results: Subjects had elevated BMI (30 ± 1 kg/m2), blood pressure (121 ± 2/77 ± 1 mmHg), and LDL cholesterol (120 ± 5 mg/dL). Following the WD, Roseburia [relative abundance (RA) = 4.2%, linear discriminant analysis (LDA) = 4], Eubacterium eligensgroup (RA = 1.4%, LDA = 4), LachnospiraceaeUCG001 (RA = 1.2%, LDA = 3.2), Lachnospiraceae UCG004 (RA = 1.0%, LDA = 3), and Leuconostocaceae (RA = 0.03%, LDA = 2.8) were most abundant relative to taxa in the SWD (P ≤ 0.05 for all). The WD was also enriched in Gordonibacter relative to the WFMD. Roseburia (3.6%, LDA = 4) and Eubacterium eligensgroup (RA = 1.5%, LDA = 3.4) were abundant following the WFMD, and Clostridialesvadin BB60group(RA = 0.3%, LDA = 2) and gutmetagenome (RA = 0.2%, LDA = 2) were most abundant following the ORAD relative to the SWD (P ≤ 0.05 for all). Lachnospiraceae were inversely correlated with blood pressure and lipid/lipoprotein measurements following the WD. Conclusions: The results indicate similar enrichment of Roseburia following the WD and WFMD, which could be explained by the fatty acid composition. Gordonibacter enrichment and the inverse association between Lachnospiraceae and cardiovascular risk factors following the WD suggest that the gut microbiota may contribute to the health benefits of walnut consumption in adults at cardiovascular risk. This trial was registered at clinicaltrials.gov as NCT02210767. J Nutr 2019;00:1–12.

Admin INCby Admin

Colon cancer prevention with walnuts: A longitudinal study in mice from the perspective of a gut enterotype-like cluster.

There is limited understanding of how walnut consumption inhibits the development of colorectal cancer(CRC). A possible mechanism may involve alterations to the gut microbiota. In this study, the effects of walnut on gut microbiota was tested in a mouse tumor bioassay using the colonotropic carcinogen, azoxymethane (AOM) added to the Total Western Diet (TWD). 16S rRNA pyrosequencing identified 3 enterotype-like clusters (E1, E2, E3) in this murine model. E1, E2 and E3 are associated with AOM exposure, walnut consumption and TWD diet, respectively. E2 and E3 showed distinct taxonomic and functional characteristics, while E1 represented an intermediate state. At the family level, E1 and E3 were both enriched with Bacteroidaceae, but driven by two different OTUs (OTU-2 for E1, OTU-4 for E3). E2 was overrepresented with Porphyromonadaceae and Lachnospiraceae, with OTU-3 (family Porphyromonadaceae) as the 'driver' OTU for this cluster. Functionally, E3 is overrepresented with genes of glycan biosynthesis and metabolism, xenobiotic metabolism and lipid metabolism. E2 is enriched with genes associated with cell motility, replication and repair, and amino acid metabolism. Longitudinally, E2 represents the gut microbial status of early life in these mice. In comparison with E1 and E3, E2 is associated with a moderate lower tumor burden (p=0.12). Our results suggest that walnuts may reduce the risk of CRC within a Western diet by altering the gut microbiota. Our findings provide further evidence that CRC risk is potentially modifiable by diet via alterations to the microbiota.

Admin INCby Admin

Does Nut Consumption Reduce Mortality and/or Risk of Cardiometabolic Disease? An Updated Review Based on Meta-Analyses.

Aim We aimed to determine if nut consumption decreases mortality and/or the risk of cardiometabolic diseases based on updated meta-analyses of epidemiological and intervention studies. Methods. An updated electronic search was conducted in PubMed/MEDLINE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and the Cochrane Library databases for original meta-analyses to investigate the effects of nut consumption on cardiometabolic disease in humans. Results. Seven new meta-analyses were included in this updated review. Findings similar to our previous review were observed, showing that nut consumption significantly decreased cardiovascular disease (CVD) mortality (-19% to -25%; n = 4), coronary heart disease (CHD) mortality (-24% to -30%; n = 3), stroke mortality (-17% to -18%; n = 3), CVD incidence (-15% to -19 %; n = 4), CHD [or coronary artery disease (CAD)] incidence (-17% to -34%; n = 8), and stroke incidence (-10% to -11%; n = 6) comparing high with low categories of nut consumption. Fasting glucose levels (0.08 to 0.15 mmol/L; n = 6), total cholesterol (TC; 0.021 to 0.30 mmol/L; n = 10), and low-density lipoprotein cholesterol (LDL-C; 0.017 to 0.26 mmol/L; n = 10) were significantly decreased with nut consumption compared with control diets. Body weight and blood pressure were not significantly affected by nut consumption. Conclusion. Nut consumption appears to exert a protective effect on cardiometabolic disease, possibly through improved concentrations of fasting glucose, total cholesterol, and LDL-C.

Admin INCby Admin

Crystallisation and glass transition behaviour of Chilean raisins in relation to their sugar compositions.

The effects of sugar component ratio, water fraction, and storage conditions on crystallisation and glass transition temperature (Tg) of three Chilean dried raisins were examined by using differential scanning calorimetry (DSC), polarised light microscopy and X-ray diffraction (XRD) techniques. Thompson, Flame and Golden raisins differed in fructose:glucose and glucose:water ratios, impacting on their measured Tgs (P < 0.05) and propensity of sugaring. The ratios of fructose:glucose (1:3, 1:2 and 1:1) and glucose:water (1.7, 1.9 and 2.1) also influenced the measured Tgs (P < 0.05) and sugaring of fructose-glucose-water model solutions. Measurement of Tgs in the raisins as a function of water activity (aw 0.11-0.74) showed that water acts as a strong plasticiser decreasing the Tgs (-16.4 to -61.6 °C). XRD results revealed that sugaring in Thompson raisins was delayed at low temperatures (5 & 15 °C) compared to that stored at 25 °C. The refrigeration may be a simple approach to delay the sugaring in raisins.

Admin INCby Admin

Effects of osmotic dehydration (with and without sonication) and pectin-based coating pretreatments on functional properties and color of hot-air dried apricot cubes.

The objective of this study was to investigate the effect of osmotic dehydration (with and without sonication) and the use of different types of edible coating on functional and color parameters of dried apricot. Osmotic pretreatment was carried out in sorbitol solution of 35 °Brix at 55 °C for 30 and 45 min. Two levels of ultrasound frequency (25 and 35 kHz) were tested. Samples were coated using pectin + citric acid (CA), pectin + ascorbic acid (AA) and pectin alone after osmotic treatment and were dried at 60 °C. The results revealed that ultrasound assisted osmotic dehydration (UOD) led to the loss of total phenolic compounds (TPC) and vitamin C compared to osmotic dehydration (OD). TPC and β-carotene contents decreased with the increase in sonication frequency from 25 to 35 kHz. However, UOD pretreated samples showed higher antioxidant capacity and β-carotene content than OD apricots. OD improved color of hot-air dried apricot compared to UOD pretreatment. The use of pectin + AA coating increased TPC and vitamin C retention and total antioxidant activity of OD or UOD pretreated samples compared to pectin or pectin + CA coatings. UOD and pectin + AA coated samples showed lower L* and b*, and higher a* values, whereas coating with CA improved color of dried apricot cubes. Coatings containing CA or AA promoted β-carotene retention in dried apricot pretreated by OD and UOD.

Admin INCby Admin

Developing Gold Nanoparticles-Conjugated Aflatoxin B1 Antifungal Strips.

Lateral flow immunochromatographic assays are a powerful diagnostic tool for point-of-care tests, based on their simplicity, specificity, and sensitivity. In this study, a rapid and sensitive gold nanoparticle (AuNP) immunochromatographic strip is produced for detecting aflatoxin B1 (AFB1) in suspicious fungi-contaminated food samples. The 10 nm AuNPs were encompassed by bovine serum albumin (BSA) and AFB1 antibody. Thin-layer chromatography, gel electrophoresis and nuclear magnetic resonance spectroscopy were employed for analysing the chemical complexes. Various concentrations of AFB1 antigen (0-16 ng/mL) were tested with AFB1 antibody-BSA-AuNPs (conjugated AuNPs) and then analysed by scanning electron microscopy, ultraviolet-visible spectroscopy, and Zetasizer. The results showed that the AFB1 antibody was coupled to BSA by the N-hydroxysuccinimide ester method. The AuNPs application has the potential to contribute to AFB1 detection by monitoring a visible colour change from red to purple-blue, with a detection limit of 2 ng/mL in a 96-well plate. The lateral flow immunochromatographic strip tests are rapid, taking less than 10 min., and they have a detection capacity of 10 ng/g. The smartphone analysis of strips provided the results in 3 s, with a detection limit of 0.3 ng/g for AFB1 when the concentration was below 10 ng/g. Excellent agreement was found with AFB1 determination by high-performance liquid chromatography in the determination of AFB1 among 20 samples of peanuts, corn, rice, and bread.

Admin INCby Admin

Low-cost sugarcane bagasse and peanut shell magnetic-composites applied in the removal of carbofuran and iprodione pesticides.

In the present study, two agro-industrial wastes, sugarcane bagasse, and peanut shell were employed as support of magnetite nanoparticles for the synthesis of magnetic bio-composites: magnetic sugarcane bagasse (MBO) and magnetic peanut shell (MPSo). The presence of magnetite was verified by Raman spectroscopy. Magnetic nanoparticles shape and size distribution were studied by TEM, while composites morphologies were observed by SEM. Structural characteristics of the pesticides and their possible chemical adsorption on composites were analyzed by FTIR. The removal was carried out by a batch adsorption process, and UV-VIS technique was used for pesticide concentration estimation. Elovich model described better all systems pointing out to a chemical adsorption process occurring. Experimental data isotherms of carbofuran and iprodione can be best explained by more than one mathematical model, but Sip was the ordinary equation in all systems. Maximum adsorption capacities of 175 and 89.3 mg/g for carbofuran, and 119 and 2.76 mg/g for iprodione, were obtained for MBo and MPSo, respectively.

Admin INCby Admin

Sensitivity programmable ratiometric electrochemical aptasensor based on signal engineering for the detection of aflatoxin B1 in peanut.

Accurately monitoring of aflatoxin B1 (AFB1), the most hazardous mycotoxin in agricultural products, is essential for the public health, but various testing demands (e.g. detection range, sensitivity) for different samples can be challenging for sensors. Here, we developed a sensitivity-programmable ratiometric electrochemical aptasensor for AFB1 analysis in peanut. Thionine functionalized reduced graphene oxide (THI-rGO) served as reference signal generator, ferrocene-labelled aptamer (Fc-apt) output the response signal. During analysis, the formation of Fc-apt-AFB1 complex led to its stripping from the electrode and faded the current intensity of Fc (IFc), while the current intensity of THI (ITHI) was enhanced. And ratiometric detection of AFB1 was achieved by using the current intensity ratio (ITHI/IFc) as quantitative signal. Compared with ratiometric strategies that highly rely on the labelled aptamers, the proposed strategy could regulate the value of ITHI/IFc by changing the modification of Fc-apt. And the detection sensitivity was found to be closely related to ITHI/IFc. Under the optimal conditions, the fabricated aptasensor with a dynamic range from 0.05-20 ng mL-1 and a detection limit of 0.016 ng mL-1 for AFB1 analysis. Besides, it exhibited excellent selectivity, reliability and reproducibility. The proposed sensitivity-programmable biosensor can be applied to detect various aptamer-recognized mycotoxins in agricultural sensing.

Admin INCby Admin

Exogenous β‐aminobutyric acid application attenuates Aspergillus decay, minimizes aflatoxin B1 accumulation and maintains nutritional quality in fresh in hull pistachio kernels

Background: Pistachio fruits suffer from postharvest decay, caused by Aspergillus flavus, resulted in aflatoxin B1 (AFB1) accumulation in kernels, which is hazardous for human health due to its carcinogenic activity. In this study, the mechanism recruited by exogenous β-aminobutyric acid (BABA) treatment for attenuating Aspergillus decay, minimizing aflatoxin B1 (AFB1) accumulation and maintaining nutritional quality in fresh in hull pistachio kernels, infected by A. flavus, during storage at 25 °C for 18 days was investigated. Result: Results of in vivo assay showed that the spore germination and germ tube elongation of A. flavus repressed by BABA treatment at 7.5 mM. Also, Aspergillus decay accompanied by AFB1 accumulation minimized in fresh in hull pistachio kernels treated with BABA at 7.5 mM and infected by A. flavus. Also, fresh in hull pistachio kernels, infected by A. flavus, treated with BABA at 7.5 mM exhibited higher phenols and flavonoids accumulation and DPPH scavenging capacity accompanied by higher PAL enzyme activity. Conclusion: Therefore, promoting phenylpropanoid pathway activity representing by higher PAL enzyme activity in fresh in hull pistachio kernels treated with BABA not only may be operative for attenuating kernels Aspergillus decay by cell wall fortifying but also may be favorable for maintaining kernels nutritional quality by ROS scavenging capacity. Also, since oxidative stress representing by ROS accumulation is responsible for A. flavus growth and AFB1 accumulation, higher phenols and flavonoids accumulation in fresh in hull pistachio kernels treated with BABA may be beneficial for attenuating Aspergillus decay and minimizing AFB1 accumulation. 

Admin INCby Admin

The potential of the pecan nut cake as an ingredient for the food industry.

Pecan nut [Carya illinoinensis (Wangenh.) K. Koch] cake (PNC) is a co-product from the oil extraction industry and its potential as an ingredient for the food industry are not well known. In this work, the nutritional composition and the functional properties of PNC were studied. Additionally, the influence of different solvents (ethanol, water, and acetic acid) on the phytochemical composition and antioxidant capacity (reducing potential of the hydrophilic compounds - RPHC, 2,2-diphenyl-1-picrylhydrazyl - DPPH, and total reducing capacity - TRC) of PNC extracts were established using a simplex-centroid design. PNC is a source of carbohydrates, protein, and dietary fiber (40.5; 21.87 and 13.01 g 100 g-1, respectively). The PNC exhibited a low energy value when compared to the raw nut (398.8 kcal 100 g-1 and 645.54 kcal 100 g-1, respectively). Mg, Mn and Co (416.74; 23.21 mg 100 g-1 and 59.00 μg 100 g-1, respectively) were the main minerals identified in PNC. The PNC also presented functional properties such as emulsifying and oil absorption capacities and a great ability to absorb water. Using the proposed solvent mixture system, the content of total phenolic compounds and condensed tannins recovered from PNC ranged between 172.43 and 2744.24 mg GAE 100 g-1, and 253.42 to 1376.44 mg CE 100 g-1, respectively. The antioxidant capacity of the PNC extract was showed through its ability to reduce hydrophilic (172.06-1714.96 mg GAE 100 g-1) to transfer hydrogen atoms (12.55-74.11% scavenging activity) and lipophilic compounds (509.87-2070.80 mg QE 100 g-1) using RPHC, DPPH, and TRC methods, respectively. Combining ethanol, water, and acetic acid at 30 °C for 15 min, positively affects the extraction of bioactive compounds from PNC, as well as the antioxidant activity of the extracts. The physicochemical, functional, phytochemical, and antioxidant properties demonstrate that pecan nut cake may represent a potential ingredient or additive for the food, pharmaceutical, and cosmetic industries.

Admin INCby Admin