Neem Oil: A Comprehensive Analysis of Quality and Identity Parameters

Abstract

Background: Neem seed oil (Azadirachta indica A. Juss) is widely used in the pharmaceutical, agricultural, and food industries due to its antiseptic, fungicidal, pesticidal, and antioxidant properties, attributed to over 300 bioactive compounds and a high content of unsaturated fatty acids. Methods: This study aimed to characterize a commercial sample of neem oil regarding its physicochemical properties and identity profile, using official methodologies from the American Oil Chemists’ Society (AOCS), and to compare the results with literature data. Results: The sample exhibited the following parameters: free fatty acids (2.0 ± 0.02%), acidity index (3.9 ± 0.04 mg KOH/g), peroxide value (3.2 ± 0.1 mEq/kg), iodine value (116 ± 12 g I2/100 g), and saponification index (198 ± 8 mg KOH/g). The predominant coloration was yellowish, with total chlorophyll and carotenoid levels below the equipment’s quantification limits. Fatty acid composition was mainly long-chain (C16–C18), with notable levels of linoleic acid (46%), oleic acid (28%), palmitic acid (12%), linolenic acid (5.5%), and stearic acid (4.1%). The triacylglycerol profile showed a predominance of triunsaturated (51%) and diunsaturated species (41%). Differential scanning calorimetry (DSC) analysis revealed crystallization events between −6 ◦C and −57 ◦C and fusion events between −44 ◦C and −1 ◦C, consistent with the high unsaturation level of the lipids. Conclusions: The analyzed neem oil sample meets quality and identity criteria, making it suitable for various industrial applications. The characterization confirms its potential and aligns with literature data, emphasizing its relevance for industrial use.