Fermenting kale (Brassica oleracea L.) enhances its functional food properties by increasing accessibility of key phytochemicals and reducing antinutritional factors.

The properties of kale as a functional food are well established. We sought to determine how fermentation further enhances these properties. We tested different fermentation conditions: (i) spontaneous fermentation with naturally occurring bacteria, (ii) spontaneous fermentation with 2% salt, (iii) Lactococcus lactis, (iv) Lactobacillus acidophilus, (v) mixture of L. lactis and L. acidophilus, (vi) mixture of L. lactis, L. acidophilus, and Clostridium butyricum. We quantified selected bioactive components using high-performance liquid chromatography (HPLC) and antinutritional factors using a gravimetric method and spectrophotometry. We then determined (i) the antioxidant capacity of the vegetable, (ii) anti-inflammation capacity, and (iii) the surface microbiota composition by 16S sequencing. All fermentation methods imparted some benefits. However, fermentation with mixed culture of L. lactis and L. acidophilus was most effective in increasing polyphenols and sulforaphane accessibility, increasing antioxidant activity, and reducing antinutritional factors. Specifically, fermentation with L. lactis and L. acidophilus increased total polyphenols from 8.5 to 10.7 mgGAE/g (milligrams of gallium acid equivalent per gram) and sulforaphane from 960.8 to 1777 µg/g (microgram per gram) but decreased the antinutritional factors oxalate and tannin. Total oxalate was reduced by 49%, while tannin was reduced by 55%-65%. The antioxidant capacity was enhanced but not the anti-inflammation potential. Both unfermented and fermented kale protected equally against lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophages and prevented increases in inducible nitric oxide synthase (iNOS), tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1ß), and interleukin-6 messenger RNA (IL-6 mRNA) expression by 84.3%, 62%, 68%, and 85.5%, respectively. Unfermented and naturally fermented kale had high proportions of sulfur reducing Desulfubrio and Proteobacteria usually associated with inflammation. Fermenting with L. lactis and/or L. acidophilus changed the bacterial proportions, reducing the Proteobacteria while increasing the genera Lactobacilli and Lactococcus. In summary, fermentation enhances the well-known beneficial impacts of kale. Fermentation with mixed cultures of L. lactis and L. acidophilus imparts higher benefits compared to the single cultures or fermentation with native bacteria present in the vegetable.

Resistance to Diet Induced Visceral Fat Accumulation in C57BL/6NTac Mice Is Associated with an Enriched Lactococcus in the Gut Microbiota and the Phenotype of Immune B Cells in Intestine and Adipose Tissue.

Humans and rodents exhibit a divergent obesity phenotype where not all individuals exposed to a high calorie diet become obese. We hypothesized that in C57BL/6NTac mice, despite a shared genetic background and diet, variations in individual gut microbiota function, immune cell phenotype in the intestine and adipose determine predisposition to obesity. From a larger colony fed a high-fat (HF) diet (60% fat), we obtained twenty-four 18-22-week-old C57BL/6NTac mice. Twelve had responded to the diet, had higher body weight and were termed obese prone (OP). The other 12 had retained a lean frame and were termed obese resistant (OR). We singly housed them for three weeks, monitored food intake and determined insulin resistance, fat accumulation, and small intestinal and fecal gut microbial community membership and structure. From the lamina propria and adipose tissue, we determined the population of total and specific subsets of T and B cells. The OP mice with higher fat accumulation and insulin resistance harbored microbial communities with enhanced capacity for processing dietary sugars, lower alpha diversity, greater abundance of Lactobacilli and low abundance of Clostridia and Desulfobacterota. The OR with less fat accumulation retained insulin sensitivity and harbored microbial communities with enhanced capacity for processing and synthesizing amino acids and higher diversity and greater abundance of Lactococcus, Desulfobacterota and class Clostridia. The B cell phenotype in the lamina propria and mesenteric adipose tissue of OR mice was characterized by a higher population of IgA+ cells and B1b IgM+ cells, respectively, compared to the OP. We conclude that variable responses to the HF diet are associated with the function of individuals' gut microbiota and immune responses in the lamina propria and adipose tissue.

The Vegetable 'Kale' Protects against Dextran-Sulfate-Sodium-Induced Acute Inflammation through Moderating the Ratio of Proinflammatory and Anti-Inflammatory LPS-Producing Bacterial Taxa and Augmenting the Gut Barrier in C57BL6 Mice.

Kale (Brassica oleracea var. acephala), a food rich in bioactive phytochemicals, prevents diet-induced inflammation and gut dysbiosis. We hypothesized that the phytochemicals protect against the lipopolysaccharide (LPS)-induced acute inflammation which results from gut dysbiosis and loss of gut barrier integrity. We designed this study to test the protective effects of the whole vegetable by feeding C57BL/6J mice a rodent high-fat diet supplemented with or without 4.5% kale (0.12 g per 30 g mouse) for 2 weeks before administering 3% dextran sulfate sodium (DSS) via drinking water. After one week, DSS increased the representation of proinflammatory LPS (P-LPS)-producing genera Enterobacter and Klebsiella in colon contents, reduced the representation of anti-inflammatory LPS (A-LPS)-producing taxa from Bacteroidales, reduced the expression of tight junction proteins, increased serum LPS binding protein, upregulated molecular and histopathological markers of inflammation in the colon and shortened the colons. Mice fed kale for 2 weeks before the DSS regime had a significantly reduced representation of Enterobacter and Klebsiella and instead had increased Bacteroidales and Gram-positive taxa and enhanced expression of tight junction proteins. Downstream positive effects of dietary kale were lack of granuloma in colon samples, no shortening of the colon and prevention of inflammation; the expression of F4/80, TLR4 and cytokines 1L-1b, IL-6, TNF-a and iNOS was not different from that of the control group. We conclude that through reducing the proliferation of P-LPS-producing bacteria and augmenting the integrity of the gut barrier, kale protects against DSS-induced inflammation.

Malting quality of seven genotypes of barley grown in Nepal.

There has been very limited work on the malting quality of barley grown in Nepal. This work used completely randomized experiment for seven barley genotypes, namely Xveola-45, Coll#112-114/Muktinath, Xveola-38, Solu uwa, NB-1003/37-1038, NB-1003/37-1034, and Bonus, collected from Hill Crop Research Program (Dolakha, Nepal) to study the effect of genotypes on the chemical composition and functional properties of barley and malt. Barley was steeped for 24 hr followed by 72 hr germination in room temperature (25 ± 3°C). Germinated barley was dried (45°C/6 hr, 50°C/4 hr, 55°C/8 hr, 70°C/1 hr, 80°C/3 hr) in a cabinet drier. Multistage dried barley was then ground to pass through a 250 µm screen. Among the chemical composition, protein and reducing sugar were affected by genotype (p < .05) in barley except for ß-glucan. Functional properties, particularly bulk density, water absorption capacity, oil absorption capacity, and viscosity, were affected by genotype (p < .05) in barley, whereas except for density, all the parameters were different (p < .05) for malt. The highest diastatic power among all genotypes was recorded for solu uwa (329.25 ºDP) followed by Muktinath (271.15 ºDP). There was no significant change (p < .05) in a protein of all genotypes after malting, whereas ß-glucan and viscosity significantly decreased (p < .05) for all genotypes after malting. The remaining parameters for all genotypes were not affected (p < .05) by malting. Solu uwa had higher enzymatic activity, whereas Xveola-38 and Muktinath were found to be better for complimentary food preparation.

Malting and fermentation effects on antinutritional components and functional characteristics of sorghum flour.

The research was aimed to observe the effect of malting and fermentation on antinutritional component and functional characteristics of sorghum flour. For whole sorghum flour, cleaned sorghum grain was milled to pass through 40 mesh sieve. For malting, cleaned sorghum grain was steeped in 0.2% calcium hydroxide solution for 24 hr and then germinated for 48 hr at 90% RH and 27 ± 2°C. Sprout was removed, dried in hot air oven at 50 ± 2°C for 24 hr and milled to pass through 40 mesh sieve. For fermented sorghum flour, 13.3 mg% diastase and 2 mg % pepsin (on the basis of whole sorghum flour weight) was added to cooked (88 ± 2°C) sorghum flour and left for 1 hr. Lactobacillus plantarum (107 cfu/g) was inoculated and incubated at temperature 30 ± 2°C for 48 hr. The fermented slurry was dried at 50 ± 2°C in hot air oven for 24 hr and milled to pass through 40 mesh sieve. The lower yield of sorghum flour was obtained compared to whole and malted sorghum flour. Germination of sorghum reduced phytate, tannin, and oxalate by 40%, 16.12% and 49.1%, respectively, whereas fermentation of sorghum flour reduced above by 77%, 96.7% and 67.85%, respectively. There was no significant change in hydrogen cyanide in malted sorghum flour compared to whole sorghum flour, but fermentation of sorghum flour reduced hydrogen cyanide by 52.3%. Bulk density and viscosity was significantly reduced by the malting and fermentation, whereas water absorption capacity and oil absorption capacity was markedly increased by the malting and fermentation. Fermented flour was good due to reduced ANF and improved functional property despite of lower yield.