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The aims of the present work were to isolate and identify the principal yeasts present in spoiled Argentine strawberry juice, identify polyphenols present in four blueberry cultivars and use these blueberry extracts in the control of yeasts using strawberry juice as food system model. Hanseniaspora osmophila and Starmerella bacillaris were identified for the first time in Argentine strawberry juice. The blueberry extracts assayed showed antifungal activity against H. osmophila and S. bacillaris through individual phenolic compounds such as quercetin, kaempferol and chlorogenic, ρ-coumaric and ellagic acid. The cytotoxicity assay demonstrated that the blueberries were not toxic to humans and that they did not modify the sensorial qualities of strawberry juice. No viable S. bacillaris and H. osmophila cells were detected after 7 days in strawberry juice supplemented with 150 μg/ml Blue Crisp or Millennium extract, inoculated with the isolated spoilage yeasts and conserved at 4 °C. This is the first evidence of S. bacillaris and H. osmophila in spoiled Argentine strawberry juice and blueberry extracts could be a good natural and non-toxic alternative to prevent growth of these yeasts. Blueberry extracts could be feasible alternatives to improve the microbiological quality without impact on the organoleptic properties of polyphenol-enriched strawberry juice. [ABSTRACT FROM AUTHOR]

The morphological and chemical characterization of Rosa sweginzowii Koehne fruit, which belongs to the Rosa section (formerly Cinnamomeae), as a source of valuable bioactive compounds is presented. The chemical composition of rose hips was evaluated in terms of the total content of anthocyanins (TAC), phenolics (TPC), and flavonoids (TFC) by spectrophotometry, and ellagic acid concentration by spectrofluorimetry (as borax complex). Morphology of fruit in macro- and microscale (by Scanning Electron Microscopy) and the presence of selected elements by Energy Dispersive X-Ray Spectroscopy were examined. The free ellagic acid content was found at a high level (16.101–24.465 mg/100g dw), and the one of total ellagic acid, after hydrolysis, was in the range of 20.244–29.771 mg/100g dw. Estimated TAC, TPC and TFC were 0.43–7.40 mg CGE/100g, 18 559–27 404 mg GAE/100g, and 10 293–14 159 mg CE/100g, respectively. Regarding the presence of valuable natural antioxidants in R. sweginzowii fruit, this plant could be used as functional food. • The morphological characterization of Rosa sweginzowii was presented. • R. sweginzowii was found to be the rich source of free ellagic acid. • TPC, TFC, TAC values proved the nutritional properties of R. sweginzowii rose hips. [ABSTRACT FROM AUTHOR]

The stability of polyphenols in muffins, enriched with strawberry, black currant, raspberry and sour cherry pomace (50 g/kg), baked in a conventional and halogen oven, at three different temperatures (140, 180 and 220 °C), was studied. The most unstable compounds were anthocyanins (36–97% lost), in contrast the flavonol glycosides were the most stable (0–21% lost). Over 100% recovery was observed for neochlorogenic acid and ellagic acid (95–120% and 341–823%, respectively). The increase of free ellagic acid content in muffins enriched with strawberry or raspberry was positively correlated with the baking time ( r = 0.879 and r = 0.944, respectively) and was the result of thermal hydrolysis of ellagitannins and ellagic acid glycosides. The highest temperature combined with a short baking time had the best effect on the preservation of polyphenols, however, since the polyphenol composition can be expected to vary in different fruits, each case should be considered separately, in order to achieve the most favorable nutritional effect of baked products enriched with fruit pomace. The sensory evaluation showed that muffins enriched with 50 g/kg of fruit pomace were competitive with control muffins, with the added benefit of having a higher nutritional value. [ABSTRACT FROM AUTHOR]

This study aimed to determine the feasibility of producing polyphenol (PPP) and pectin powders (PPE) from Georgia-grown pomegranate peels and to develop microencapsulated PPP (MPPP) powders. PPP and PPE were solvents extracted and characterized. Suspensions containing deionized water, 3 g/100 mL of PPP, and 15 g/100 mL of a blend of maltodextrin (MD):PPE of weight ratios (0:1, 3:1, 4:1, 5:1, and 1:0 g:g) were prepared and spray-dried at 140 °C inlet air temperature to produce MPPP powders. PPE had a degree of methyl esterification of 53.67%. The total polyphenol (mg GAE/mL), α-punicalagin (mg/g, dry basis, d.b.), β-punicalagin (mg/g d.b.), ellagic acid (mg/g, d.b.) content of PPP was 522.82, 108.3, 101.0, and 73.8, respectively. MPPP powders produced with higher amounts of PPE had significantly (p < 0.05) higher moisture and particle agglomeration than the rest of the powders. While MPPP powders prepared with a blend of MD:PPE had significantly (p < 0.05) higher encapsulation efficiencies (EE) (>89.90%), water solubilities (>88.09%), and antioxidant activities than the powders microencapsulated with only MD or PPE. MPPP powders produced with MD:PPE (ratio 4:1) showed the highest antioxidant activity, EE, and the particle sizes. MPPP powders with larger particles were positively correlated with higher antioxidant activities. MPPP powders may be used as novel food ingredients. [Display omitted] • High methoxyl pectin powders (PPE) were developed from pomegranate peels. • Polyphenol powders (PPP) were produced from Georgia-grown pomegranate peels. • PPP with α- and β-punicalagin and polyphenols had elevated antioxidant activities. • Microencapsulated PPP (MPPP) powders were produced with PPE and maltodextrin (MD). • MPPP powders produced with MD:PPE (ratio 4:1) had the highest antioxidant activity. [ABSTRACT FROM AUTHOR]

Abstract: The stability of phenolic compounds of three strawberry cultivars was evaluated for changes during prefreezing treatments, storage and various freezing and thawing conditions. Polyphenol content was determined by HPLC–DAD–FL. The sum of assayed polyphenolic (proanthocyanidin and monomeric flavan-3-ols, anthocyanins, ellagic acid, p-coumaric acid) represented 2858.4mg/kg in Kent, 2893.1mg/kg in Elkat, and 2438.0mg/kg in Senga Sengana. After freezing, 4.5–33.6% of polyphenols were lost; protective effects of prefreezing treatments were seen on anthocyanidins and proanthocyanidins: ascorbic acid was the most effective pretreatment, allowing retention of 3.9–27.5% of anthocyanins, and almost total recovery (3.9–23.9%) when associated with liquid nitrogen freezing. Pectin and sugar only allowed retention of 3.0–25.1% and 5.5–25.4% of the antocyanins, respectively. Thawing of the strawberries in a microwave oven (instead of 20h at 20°C) had a further positive effect on retention of anthocyanins, proanthocyanins, (+)-catechin and ellagic acid. [Copyright &y& Elsevier]