Characterization of the Biochemical Potential of Moroccan Onions (Allium cepa L.)

Abstract

Allium cepa L. remains the most cultivated Allium species in Morocco and around the world. With the purpose of making the first biochemical characterization of Moroccan onions, several biochemical components have been measured in eleven onion ecotypes. Onions were collected as seeds from different geographical origins and cultivated in the same environment, to eliminate the influence of the environment on biochemical expression. Moisture, total phenols, flavonoids, antioxidant activity, total and reducing sugars, and sulfur dioxide were the biochemical properties of interest. Except for moisture, the eleven onion ecotypes revealed a highly significant variation in terms of the studied biochemical characters. The total phenol and flavonoid content ranged from 5.94 to 11.22 mg equivalent gallic acid/g dry weight and 0.67 to 1.52 mg equivalent quercetin/g dry weight, respectively. The antioxidant activity of the studied onions showed a strong correlation with the polyphenols ( R 2 = 0.7189 ), especially with the flavonoids ( R 2 = 0.8063 ). The sulfur dioxide content parted from 85.60 to 30.43 ppm when measured using the Monier-Williams distillation method. The current results show that there is no correlation between total sugars and reducing sugars. In conclusion, these findings present a clear biochemical profile of Moroccan onion ecotypes, as well as confirm, for the first time, the presence of a clear variation between the biochemical profiles of Moroccan onion ecotypes, which could be useful for future valorization programs.

Effects of Nitrogen Source on Mineral Element, Phytochemical Content, and Antioxidant Activity of Short-Day Onion (Allium cepa) Bulbs

“…The slow-release N from CaCN 2 could contribute to amino acid formation, vital for flavonoid synthesis [40]. It is worth noting that the flavonoid content reported in this study was notably in the same range reported by Amal et al [60], whose findings indicated 0.67 mg CE g −1 in white onions.…”

The Use of Fluorescence Spectroscopic Data and Machine-Learning Algorithms to Discriminate Red Onion Cultivar and Breeding Line

“…The worth of an attribute was evaluated using the OneR classifier at the following parameters: seed for the cross-validation, 1; the number of folds for the cross-validation, 10; the minimum number of objects in a bucket, 6; using the training data to evaluate attributes rather than cross-validation, False. Ten attributes were selected to maintain the ratio of attributes (10) to the number of cases (100) of 1:10. Then, the discriminative models were developed based on selected data using a 10-fold cross-validation mode.…”

“…The chemical composition of red onion, including, e.g., the content of flavonols, anthocyanins, total phenols, sulfur dioxide, and reducing sugars, can differ depending on, among others, the cultivar, line, and ecotype [7][8][9][10]. Therefore, distinguishing different onion types may be important.…”

Numerical Simulation of the Drying Kinetics of Yellow Onions (Allium cepa) to Prevent the Growth of Aspergillus Niger

“…Due to this, the domestic demand is attained through importation [5]. In the year 2022, the Philippines Statistics Authority (PSA), reported that 12.45% of the onion supply comes from importation [6]. Yellow onions are one of the most grown onion varieties in the country.…”