Potential Prebiotic Oligosaccharide Mixtures from Acidic Hydrolysis of Rice Bran and Cassava Pulp

Cellulase-Xylanase-Treated Guava Purée by-Products as Prebiotics Ingredients in Yogurt

Fruit processing by-products may be re-utilized as prebiotic ingredients to minimize the environmental impact of solid wastes generated from food industries. This study investigated the effects of enzymatic-induced hydrolysis on two types of guava purée by-products, particularly the prebiotic activity after its inclusion in yogurt-making. Commercial cellulase and xylanase were applied together or separately on refiner (the seed-rich fraction), and decanter (the pulp-rich fraction); labelled as 150 XY (xylanase); 150 CE (cellulase), 150 CX (combined cellulase-xylanase), and CT (control, untreated). The hydrolysis extents followed the order of 150 XY < 150 CE < 150CX. The ethanolic extracts (EEC) of the treated samples were analyzed on selected sugar content and the prebiotic activity score. Rhamnose and xylose were the main sugar constituents in both refiner and decanter. A two to four-fold increments of prebiotic activity score were observed on EEC of combined cellulase and xylanase treated decanter and refiner. Incorporating the combined enzymatically treated whole guava by-products into UHT fresh milk containing a yogurt starter culture significantly increased the log CFU/mL up to 77.6%, enhanced hardness, stickiness, and adhesiveness ranging from 22.2 to 86.4%, and decreased pH values. Combined cellulase-xylanase treatment can convert guava purée by-products into potential prebiotic sources for food applications.

Turmeric Extract: Potential Use as a Prebiotic and Anti-Inflammatory Compound?

Prebiotics are regarded as the non-digestible food constituents that are selectively consumed by health-promoting bacteria (probiotics). In fact, a number of active metabolites is released due to intensive interaction between prebiotics and probiotics in the gut which exert local and systemic beneficial effects including regulation of intestinal disorders and modulation of host immunity. Turmeric is one of the most important medicinal herbaceous that is derived from Curcuma longa rhizome. Curcumin is a well-recognized component of turmeric which contributes to the prevention of multiple inflammatory diseases. Despite curcumin as a well-known compound, few researches have focused on the turmeric extract (TE) and its potential as prebiotic and anti-inflammatory compound. The aim of this study was to evaluate the prebiotic potential and some functional-structural properties of TE. The Fourier-transform-infrared spectroscopy (FTIR) spectrum of TE showed identical peaks that belonged to β configuration in pyranose and glycosidic bonds. High performance liquid chromatography (HPLC) analysis revealed the presence of potent phenolic and flavonoid anti-oxidants and curcuminoids, and some functional monosaccharides. TE demonstrated excellent resistance to artificial human gastric and intestine juice compared to the standard prebiotic (inulin) (p ≤ 0.05). Interestingly, our time course experiment showed that TE not only is digested by probiotics including Lactobacillus rhamnosus GG (LGG) and Bifidobacterium animalis BB12, but also supports the growth of these bacteria even after 72 h (p ≤ 0.05). To our knowledge, this is the first report evaluating prebiotic potential of TE and exploring its suppressive effects on LPS induced IL-8 production in HT29-19A cell line.

Cassava cell wall characterization and degradation by a multicomponent NSP-targeting enzyme (NSPase)

Cassava (Manihot esculenta Crantz) is considered the third most important source of calories in tropical regions. Up to one third of cassava harvested worldwide is used in livestock production. The focus of this study was to characterize cassava cell wall structure to provide knowledge for a better application of cassava as an energy source in monogastric animal feed. A total of five cassava samples from different feed mills in South East Asia were investigated. On a dry matter basis, the cassava cell walls contained, on average, 640 mg g⁻¹ glucose, 140 mg g⁻¹ galactose, 50 mg g⁻¹ mannose, 80 mg g⁻¹ xylose, 60 mg g⁻¹ arabinose, 10 mg g⁻¹ fucose and 20 mg g⁻¹ rhamnose. RONOZYME VP (DSM Nutritional Products, Switzerland), a non-specific multicomponent non-starch polysaccharide (NSP) degrading enzyme (NSPase) product from Aspergillus aculeatus, solubilized about 10% of cassava NSP content during 4 h incubations at 40 °C and pH 5. There was notable solubilization of polymers containing uronic acids, galactose, arabinose and rhamnose. Immuno-microscopy imaging indicated the solubilization of pectin, galactan and xyloglucan polysaccharides from cassava cell wall. As a consequence, the starch granules became more available to exogenous α-amylase degradation.

Valorizing cabbage (Brassica oleracea L. var. capitata) and capsicum (Capsicum annuum L.) wastes: in vitro health-promoting activities

The capsicum seed core and cabbage outer leaves are common wastes generated in the vegetable processing industry. We explored the in vitro health-promoting activity of these waste products for valorization. Freeze-dried and pulverized cabbage wastes had a high bile acid binding capacity and the capsicum wastes inhibited glucose dialysis more effectively. Methanolic extracts prepared with conventional solvent extraction and ultrasound-assisted extraction were analyzed to determine their 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, in vitro α-amylase inhibitory, in vitro lipase inhibitory, and prebiotic activity. Crude extracts of cabbage and capsicum wastes were screened using GC-MS analysis. The cabbage waste extracts showed high antioxidant activities but did not inhibit α-amylase. The capsicum waste extracts inhibited both lipase and α-amylase activities and supported the growth of the probiotic bacterium, Lactobacilli brevis. Volatile compounds of the vegetables consisted mainly of phenols and fatty acid esters. In all assays except the α-amylase inhibition assay, the extracts prepared with ultrasound-assisted solvent extraction showed higher activity than those prepared using the conventional method. The capsicum seed core and cabbage outer leaves are potential sources of phytochemicals and antioxidant fibers. Capsicum waste extract supported probiotic bacterial growth without a lag phase. These waste products may be processed into high-value functional ingredients.