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. This diversity is due to the wide types of fruits and pigments, such as anthocyanins in this genus, which cause red, blue, and purple colors. Raspberry species are widely distributed worldwide and have wild, cultivated species and different genotypes that are distributed from the North Pole to Australia. Raspberry fruit is rich in antioxidant compounds, especially polyphenols.
Raspberries contain many compounds that include vitamins such as E, C, A, acetic acid, mineral chloride, Fe, Co, Mn, Al, Cu, and Zn. The importance of natural antioxidants in human health and reducing the risks of heart disease, cancer, and diabetes has led to much attention being paid to the use of these compounds. Phenolic compounds in plant samples are one of the best sources of natural antioxidants, and raspberry fruit is one of the most important sources of polyphenolic compounds that have received less attention so far. Raspberry phenolic compounds prevent oxidation and liposomes in the body and significantly eliminate free radicals.
Various studies have proved that the total antioxidant activity of raspberries, total phenols, and flavonoids was significantly higher than strawberries, so the antioxidant properties of raspberries were about twice that of strawberries. The amount of phenol and anthocyanin in raspberries is significantly higher than in cherries and plums. Total phenol content in the ripe berries is more than unripe fruits to handle the increased amount of phenolic compounds. Free radicals are electrophiles that damage cellular components and destroy proteins, lipids, and, most importantly, nucleic acids, and cause oxidative stress. Increased oxidative stress in people with diabetes leads to a wide range of diseases such as retinopathy, nephropathy, neuropathy, cardiovascular disease, and sexual and hormonal disorders. To counteract oxidative stress, antioxidants are molecules in which single electrons or hydrogen atoms react to free radicals in oxidized cells and tissues.
As mentioned, raspberries are a rich source of natural antioxidants because it contains large amounts of phenols, flavonols, and anthocyanins and is, therefore, a free radical scavenger. Two species of raspberry were studied to determine the amount of antioxidants, and phenolic and flavonoid compound in their fruits at three different stages of fruit ripening immature, semi-ripe and mature. Due to the fact that sufficient studies on antioxidant activity have not been performed at present, the aim of this study was to investigate the protective effects of raspberry fruit extract on antioxidant activity and mineral performance. Since fruit variety and genotype affect the biologically active compounds of raspberries, so in this study, the antioxidant activity of two types (R. idaeus and R. strigosus) of raspberries has been investigated. In this study, the fruits of two species of raspberries, R. idaeus and R. strigosus have been evaluated at different stages of fruit ripening. For this purpose, 1 g of harvested fruits was soaked in 23 mL of methanol solvent and crushed and then filtered to produce extracts.
A metabolic extract of raspberry fruits was prepared for experiments related to the measurement of antioxidants and the content of total phenol and total flavonoids. The extracts were stored in 2 mL microtubes at -23 °C in the laboratory until frozen for about six months until the beginning of the experiments. In this study, two methods were employed to assess the antioxidant activity. First, based on radical deterrence methods that aim to calculate radical inhibition, Second, the ability of antioxidants in lowering Ferric acid to see the antioxidant power in converting Fe2+ into Fe3, Third and fourth is the measurement of the total content of phenols and flavonoids.
The result from this study shows 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. Therefore, the consumption of fruit in the full ripening stage is recommended to fight against various cancers and diseases.
Details of the article can be accessed through this link :
Title: Determination of the antioxidant and mineral contents of raspberry varieties
Authors: Shehla Shoukat, Trias Mahmudiono, Sarmad Ghazi Al-Shawi, Walid Kamal Abdelbasset, Ghulam Yasin, Rustem Adamovich Shichiyakh, Acim Heri Iswanto, Abed Jawad Kadhim, Mustafa Mohammed Kadhim, Heba Qassim Al–Rekaby
