Evaluation of Some Biochemical Compounds and Juice Color Indices in Pomegranate Genotypes of Oraman Region (Kurdistan Province)

Document Type : Full Paper

Authors

• Salman Sharifi
• Mokhtar Heidari
• Mostafa Rahmati Joneid Abad

Department of Horticultural Science, Agricultural Sciences and Natural Resources University of Khuzestan, Mollasani, Iran

Abstract

Keywords

• Anthocyanin
• Antioxidant compounds
• Genetic diversity
• Flavonoids
• Phenolics
• Pomegranate

Main Subjects

• Fruit Science

Extended Abstract

Introduction

    Genetic diversity and the use of different cultivars and genotypes are important in pomegranate breeding and cultivation. Although, the quantitative and qualitative fruit characteristics of pomegranate genotypes have been studied in different regions of Iran, there are still regions, including Kurdistan province in the west of Iran, where no report has been published about the genetic diversity of pomegranate. The present experiment investigated the quantitative and qualitative characteristics of fourteen pomegranate genotypes collected from four regions in Oraman, Kurdistan.

Materials and Methods

This experiment was conducted in the fall of 2019 in the Oraman region (65 kilometers from Marivan, Kurdistan province). Pomegranate orchards were located in four villages, including Dergashikhan, Selin, Zhivar, and Belbar. The fruits of 14 different pomegranate trees were harvested by hand from four sides of each tree and transferred to the Department of Horticultural Sciences and Engineering (Khuzestan University of Agricultural Sciences and Natural Resources, Mollasani), following the principles of transportation, for further studies.

Biochemical indices measured in fruit juice were as follows: total soluble solids (TSS), total titratable acidity (TA), taste index (calculated by dividing total soluble solids by acidity), consumer taste acceptability index (Brima-A), ascorbic acid, total flavonoids, total phenol, total anthocyanin, total phenol to total anthocyanin ratio, anthocyanin index, the percentage of substances causing yellow, red , and blue colors (measured by light absorption at 420, 520, and 620 nm, respectively), color intensity (measured by the sum of absorbance at 420, 520 and 620 nm), pure red color index (dA) and hue value (Color Tone).

Results and Discussion

Investigating the biochemical characteristics of fruit juice showed that the amounts of total acidity, total ascorbic acid, total phenol, and total flavonoids were significantly different among different genotypes of Kurdistan pomegranates, but total soluble solids, taste index (soluble solids/acidity) and Brima-A index were not significantly different. Also, the examination of fruit color indices showed significant differences in total anthocyanin, color intensity, pure red color intensity, browning compounds, and the ratio of total phenol to anthocyanin.

Conclusions

Based on the results of the present experiment, it was found that biochemical characteristics, total anthocyanin, color intensity, and aril color indices were significantly different in pomegranate fruits of the Oraman region of Kurdistan. The differences in color indices such as color index, red color percentage, color intensity, and K-K index in the pomegranate fruits showed that in addition to total anthocyanin, other color indicators can be used to evaluate the quality of pomegranate juice. Furthermore, the results related to the difference in the amounts of total anthocyanin, total phenolic, and ascorbic acid indicate a difference in the antioxidant capacity of pomegranate juice in this region. Conducting more studies on the biochemical characteristics of the skin and seeds of pomegranates in the Oraman region of Kurdistan could be used to collect information related to the genetic resources of pomegranates in Iran and to identify the best pomegranate populations in this region.