Comparison of Bioactive Components, Antimicrobial and Antimutagenic Features of Organically and Conventionally Grown Almond Hulls

Abstract

In Turkey, almonds are grown via the following three methods: organic (O), conventional (C) and good agricultural practice (GAP). Almond seeds are mostly consumed as nuts; thus, the researchers have focused different analyses on only seeds. However, in Turkey, unripe green almond hulls are also consumed. Therefore, we studied the contents of some bioactive components, pigments, and malondialdehyde (MDA) and the antimicrobial, antioxidant, and antimutagenic activities of O, C, and GAP 'Ferradual' (Frd) and 'Ferragnes' (Frg) almond hull extracts. The highest total ascorbic acid content was found in O Frd (2.1 mg/g fresh weight [FW]) and GAP Frg (2.0 mg/g FW). The total phenolic content and total flavonoid content in all the genotypes ranged from 19.2 and 43.9 mg/g FW and 3.2 and 20.2 mg/g FW, respectively. In general, the antioxidant activity of C Frg and C Frd was low. C Frg had the highest MDA content (8.53 µmol MDA/g FW), whereas O Frg had the lowest MDA content (0.89 µmol MDA/g FW). The samples had varying ratios of chlorophyll a and b. The O samples had more total carotenoid content than the C samples. The antibacterial activity was only observed in the O and GAP Frd extracts. The antifungal activity could not be detected in any of the extracts of samples. Varying antimutagenic activity in Salmonella typhimurium TA 98 strain and content of some phenolics were observed depending on the variety, growing conditions, and dose.

Lipid characteristics, bioactive properties, and mineral content in hazelnut grown under different cultivation systems

“…As seen in Figures 1, 26% more phenolic compounds were detected in OHs than in CHs. Murathan et al (2020) found higher TPC in organic almond hull, similar to our study. However, in our previous study conducted on Levant hazelnuts, no difference between production systems was detected (Karaosmanoglu & Ustun, 2021).…”

“…Consistent with this study, Yang et al (2009) detected 113.7 mg CE/100 g sample TFC in hazelnut. Murathan et al (2020) reported higher levels of TFC in organic almond hull. The use of pesticides and artificial fertilizers can cause an increase in ROS (reactive oxygen species) and cause stress in the plant (Murathan et al, 2020).…”

“…Murathan et al (2020) reported higher levels of TFC in organic almond hull. The use of pesticides and artificial fertilizers can cause an increase in ROS (reactive oxygen species) and cause stress in the plant (Murathan et al, 2020). Exposure of plants to aggressive and stressful situations can lead to the induction of secondary metabolic processes, which results in higher rates and amounts of phenolic compounds to be synthesized (Pertuzatti et al, 2015).…”

“…The belief among consumers that organic foods are more nutritious has prompted researchers to investigate the composition and quality of many organic foods to prove this hypothesis. Therefore, some researchers have compared the physical, chemical, and nutraceutical properties of organically and conventionally grown tomato, banana, orange, apple, papaya, mango, tangerine (Faller & Fialho, 2010), passion fruit (Pertuzatti et al, 2015), cashew nut (Soares et al, 2013), and almond hull (Murathan et al, 2020).…”

Effect of almond hulls on the performance, egg quality, nutrient digestibility, and body composition of laying hens

“…Egg yolk color is influenced by the deposition of dietary pigments such as beta-carotene, riboflavin and zeaxanthin ( Damron et al, 1984 ). Almond hulls are dried almond fruit flesh containing a high amount of chlorophyll and carotenoid contents ( Murathan et al, 2020 ). A plausible explanation of the egg yolk color difference observed here between 15% almond hull inclusion rate and control group is the pigments from almond fruit and a reduction of corn in the diets.…”