Lana Fukumoto

In Vitro Bioavailability of Phenolic Compounds from Five Cultivars of Frozen Sweet Cherries (Prunus avium L.)

The bioavailability of phenolic compounds from five cultivars of frozen sweet cherries was assessed by a digestion process involving pepsin-HCl digestion (to simulate gastric digestion) and pancreatin digestion with bile salts (to simulate small intestine conditions) and dialyzed to assess serum- and colon-available fractions. After pepsin digestion, the % recovery of total phenolics, relative to the original starting material, increased, whereas the % anthocyanins did not change. Following pancreatic digestion and dialysis, the total phenolics in the IN (serum-available) fraction was about 26-30% and the OUT (colon-available) fraction was about 77-101%. The anthocyanin content in the IN fraction was 15-21%, and in the OUT fraction, it was 52-67%. Skeena, Lapins, and Sweetheart cultivars contained higher levels of total phenolics and anthocyanins, which resulted in higher concentrations of these compounds in the IN and OUT fractions. The potential bioavailability of phenolic compounds was also assessed in Bing and Lapins cultivars at three ripening stages. Immature cherries had higher % total phenolics in the IN fraction than mature or overmature cherries. However, immature cherries had the lowest concentrations of these compounds, making the actual bioavailable amounts of these compounds lower than for mature and overmature fruit. High-performance liquid chromatography analysis of Lapins cherries at three maturity stages confirmed the results obtained using spectrophotometric methods for total phenolics and anthocyanins.

Characterization of Water Extractable Crude Polysaccharides from Cherry, Raspberry, and Ginseng Berry Fruits: Chemical Composition and Bioactivity

Water extractable crude polysaccharides from three sweet cherry varieties, raspberries, and ginseng berry pulp were evaluated for their chemical composition, structural features, molecular weight, and bioactive properties. The yields of the crude polysaccharides isolated from cherries, raspberries, and ginseng berry pulp ranged from 0.79 to 0.18% on a dry weight fruit basis. All of the crude polysaccharides contained protein, phenolic compounds, and uronic acid. Each crude polysaccharide contained the sugar monomers: rhamnose, arabinose, xylose, mannose, galactose, and glucose. Of the water extractable polysaccharides obtained from the mature fruits, the crude polysaccharides from the raspberries had the highest molecular weight while the crude polysaccharides from the ginseng berry pulp had the smallest molecular weight. Results from Fourier transform infrared spectroscopy suggested that the crude polysaccharides contained a monosaccharide with six carbon atoms in a D-glucopyranose ring and a protein component. The crude polysaccharides from cherries, raspberries, and ginseng berry pulp were shown to possess antioxidant activity as determined with the ferric reducing antioxidant power and the 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays. The effect of crude polysaccharides on: (1) caspase 3 activation, which was determined using a hypoxia/reoxygenation model, and (2) immunostimulation, which was determined by evaluating the inflammatory mediator response, were examined. Only crude polysaccharides obtained from certain varieties of sweet cherries inhibited caspase 3 activation in a dose-dependent manner, while only the crude polysaccharides obtained from ginseng berry pulp stimulated immune function. Crude polysaccharides present in small fruits do possess bioactivities that may enhance human health.

Characterization of Pilot Scale Processed Canadian Organic Cranberry (Vaccinium macrocarpon) and Blueberry (Vaccinium angustifolium) Juice Pressing Residues and Phenolic-Enriched Extractives

ABSTRACT This work examined the processing yields, physico-chemical characteristics, and bioactive properties of Canadian organic cranberry and blueberry pomace and phenolic-enriched extractives. The ethanol extracts from each berry contained three to four times the soluble solids and sugar contents compared to the pomace. The lipid content of organic cranberry pomace (4.44%), cranberry ethanol extractives (3.86%), and blueberry ethanol extractives (4.44%) were significantly lower than the lipid content of the organic blueberry pomace (5.42%). The organic blueberry pomace showed higher protein content (8.41%) than organic cranberry pomace (5.76%); however, both organic cranberry and blueberry ethanol extracts showed similarly low protein contents. Significant differences were observed in the mineral and elemental contents of both pomaces and their extractives. Total phenolics, tartaric esters, flavonols, anthocyanins, and antioxidant activities were increased by two to three times in both organic cranberry and blueberry ethanol extracts compared to their respective pomaces. The major anthocyanins detected in organic blueberry pomace and ethanol extracts were peonidin 3-glucoside, malvidin 3-galactoside, malvidin 3-glucoside, and cyanidin 3-arabinoside. Peonidin 3-galactoside, cyanidin 3-galactoside, cyanidin 3-arabinoside, and peonidin 3-arabinside were the major anthocyanins in the organic cranberry and ethanol extacts. Results indicated that cranberry and blueberry pomace could be used to develop bioactives with antioxidant activity for potential health benefit and/or bioenergy production.

Influence of variety, storage, and simulated gastrointestinal digestion on chemical composition and bioactivity of polysaccharides from sweet cherry and apple tree fruits

Abstract This work examined the effect of extraction regime (hot water vs. simulated in vitro gastrointestinal digestion) and postharvest storage on the chemical composition, molecular weight, and bioactive properties of polysaccharides obtained from sweet cherries (Lapins and Staccato varieties) and apples (Gala and Fuji varieties). The yields of the polysaccharides isolated from cherries and apples ranged from 0.2 to 2.4% on a dry weight fruit basis. All of the isolated polysaccharides contained protein, phenolic compounds, and uronic acid. All polysaccharides contained the sugar monomers: rhamnose, arabinose, xylose, mannose, galactose, and glucose. Also, all of the polysaccharides obtained using the different extraction regimes were shown to possess antioxidant activity as determined with the ferric reducing antioxidant power and the 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays. Only the polysaccharides isolated from the cherry and apples after simulated in vitro gastrointestinal digestion showed appreciable α-glucosidase inhibition activity, with polysaccharides obtained from Staccato cherries showing nearly 90% of the inhibition of α-glucosidase as achieved with the positive control acarbose. This work shows that bioactive polysaccharides are available and/or can be isolated during digestion which supports the concept that fruit polysaccharides play a role in enhancing human health.

The chemical composition, antioxidant activity and α-glucosidase inhibitory activity of water-extractable polysaccharide conjugates from northern Manitoba lingonberry

Abstract Lingonberry (Vaccinium vitis-idaea L.) is a small northern fruit that has been harvested historically by native North Americans and Northern Europeans. These berries have been traditionally consumed as food and for medicinal use. Lingonberries are reported to be rich in vitamin C, benzoic acid, and anthocyanins, which have been implicated in health benefits associated with the consumption of lingonberries. We hypothesized that water-extractable polysaccharides, conjugated with proteins and/or phenolics may also serve as bioactive compounds with potential health benefits in northern Manitoba lingonberries. A hot water extraction was used to obtain water-extractable polysaccharides from lingonberries and the water-extractable polysaccharides were fractionated into water-eluted/neutral and NaCl-eluted/acidic fractions using chromatography. The water-extractable polysaccharides were evaluated for their chemical composition and structural features. The antioxidant activity (FRAP and ABTS assays) and potential of the polysaccharides to serve as α-glucosidase inhibitors were determined. The chemical composition and structural features of the water-extractable polysaccharides were influenced by fraction. The water-extractable polysaccharides and fractions all possessed antioxidant activity, while only the water-extractable polysaccharide conjugates and NaCl-eluted/acidic fraction demonstrated appreciable α-glucosidase inhibition. This work provides novel information indicating that water-extractable polysaccharide conjugates isolated from northern Manitoba lingonberry demonstrate bioactivity.