Determination of the antioxidant and mineral contents of raspberry varieties

Abstract

Humans maintain their health by consuming a variety of vegetables and fruits that contain antioxidants, both enzymatic and no enzymatic. Raspberry is one of the most diverse genus of true dicotyledonous plants, which includes 12 subspecies and about 429 species. Raspberry fruit is rich in antioxidant compounds, especially polyphenols. Two species of raspberry were studied to determine the amount of antioxidants and phenolic and flavonoid compounds in their fruits at three different stages of fruit ripening immature, semi-ripe and mature. Natural samples of Rubus idaeus and Rubus strigosus were collected. In this study, the fruit extracts of two species were stored at -23 °C for about six months. Free radical cleansing and Ferric reducing antioxidant power methods were used to determine the antioxidant activities of the extracts. The antioxidant activity of both methods revealed a higher mean value in extracts from fully matured fruits compared with immature and semi-ripe fruits. The results showed that the antioxidant activity of Rubus strigosus is 9%, 10%, and 8% higher than Rubus idaeus in the stages of immature, semi-ripe, and full maturity, respectively.

Reconnoitring the antioxidant and antibacterial potential of different fruits after tannin acyl hydrolase mediated biotransformation

“…Previous studies also reported the presence of tannins in plum fruit. Soluble tannins present in plum peels were found to be 59.9–113.9 mg EE/100 g FW and in fruit flesh were about 31.4–58.2 mg EE/g FW 33 . Similar pattern of the presence of tannin was seen in our study with plum showing the maximum tannin amount while guava and pomegranate displaying the minimum.…”

“…Polyphenol in jamun was found to be 203 mg GAE/100 g of fresh fruit pulp 32 . TPC in fruit peel was observed to be 128.5–2020 mg ellagic acid equivalents (EE)/100 g fresh weight (FW) while in plum fruit flesh, it was estimated to be around 260.9–1080.9 mg EE/100 g FW 33 . Table 3 shows the mean and standard deviation of the TTC of all seven fruit extracts with 95% confidence intervals.…”

“…The antioxidant activity was calculated thereafter, using ABTS (2,2′‐azino‐bis(3‐ethylbenzthiazoline‐6‐sulfonic acid)) (potassium persulfate method) radical scavenging activity 32 . In another study, tea was bio‐transformed by using Penicillium charlesii tannase to improve the quality of tea and enhance its antioxidant capacity 33 . It has been observed that for DPPH assay, the IC 50 value, for P. guajava extract was reported to be 47.76 μg/mL, 35 for F. ananassa , 9.73 μg/mL, 36 for R. idaeus , 12.5 μg/mL, 37 for R. fruticosus 42.51 μg/mL, 38 for P. domestica 24.45 μg/mL, 39 for S. cumini 0.278 mg/mL, 40 and for P. granatum 39.24 μg/mL, 41 respectively.…”

“…32 TPC in fruit peel was observed to be 128.5-2020 mg ellagic acid equivalents (EE)/100 g fresh weight (FW) while in plum fruit flesh, it was estimated to be around 260.9-1080.9 mg EE/100 g FW. 33 Table 3 shows the mean and standard deviation of the TTC of all seven fruit extracts with 95% confidence intervals. For further inferences, ANOVA had been applied on the TTC data and it had been reliably predicted (R 2 99.3%) that the TTC content was significantly different among considered fruit extracts.…”

Chemical composition and antioxidant activity of date (Phoenix dactylifera L.) varieties at various maturity stages

“…Humans maintain their health by eating healthy fruits and vegetables having antioxidants. The antioxidants vary according to variety and ripening stage of fruits (Shoukat et al, 2022).…”