Antioxidant and Antimicrobial Properties of Semi-Processed Frozen Prickly Pear Juice as Affected by Cultivar and Harvest Time

Abstract

Consumer interest toward natural ingredients is creating a growing trend in the food industry and research for the development of natural products such as colorants, antimicrobials and antioxidants. Semi-processed frozen prickly pear (Opuntia ficus-indica (L.) Mill.) juices (PPJs), obtained from three cultivars with white, red and yellow pulp, with different harvest times (“Agostani” and “Bastardoni”), were characterized for betalains, total phenolics, flavonoids, carotenoids, antioxidant capacity (by 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH)) and antimicrobial potential against foodborne pathogenic bacteria. Through chemical assays, PPJs showed high contents of total polyphenols, flavonoids and betalains and marked antioxidant capacity. PPJs from the first harvest (“Agostani”) revealed the significantly highest amount of polyphenols in white cultivar and of betacyanin and betaxanthin in yellow and red cultivars; antioxidant capacity was significantly higher in “Agostani” PPJs than in “Bastardoni” ones. Regarding antimicrobial potential, all PPJs revealed good antibacterial activity, particularly against Salmonella enterica as evidenced by the widest inhibition haloes. These results encourage the suitability of the first flowering prickly pear fruits, with low market value as fresh fruit but with high nutritional features, to be processed as semi-finished product. In particular, its use as ingredient in foods with high risk of Salmonella contamination may act as a natural preservative.

Assessment of pear juice and puree as a fermentation matrix for water kefir

“…The DPPH assay revealed a scavenging ability of 58% for the unfermented juice (Figure 1), comparable to previous studies on pear juices that recorded values of 40%-84% (Di Cagno et al, 2016;Palmeri et al, 2020). As expected, the puree sample showed significantly higher antioxidant activity than the juice (25% higher) with a value of 54% (Figure 1), since fruit peel is known to contain more antioxidant compounds such as phenolics, flavonoids, and triterpenes, at levels of more than double than in the pear flesh (Li et al, 2014).…”

Evaluation of quality attributes, antioxidant activity and volatile compounds of two cactus pear juices blended with guava juice

“…The TPC in the blends of guava with green and purple cactus pear juice ranged from 62.43 mg GAE/100 mL in T4 to 82.45 mg GAE/100 mL in T3 (Table 3). The obtained values for blends indicate that juices is a rich source for polyphenols in comparison with the previous studies which mentioned that Opuntia spp juices contain polyphenols in range of 2.2-66 mg GAE/100 mL [39][40]. The blends showed a remarkable increase in total phenolic content with the increase of cactus pear in blends in formula to reach the maximum level at T3 and T6 (Table 3).…”

Characterization of Prickly Pear Peel Flour as a Bioactive and Functional Ingredient in Bread Preparation

“…However, by-products obtained by fruits and vegetables possess antimicrobial properties due to their antioxidant activity and to the high content of total polyphenols and betalains [15][16][17], therefore, the addition of such ingredients in leavened bakery products, such as bread, could negatively affect the ability of Saccharomyces cerevisiae baker's yeast to leave the dough.…”