Geographical origin classification of peanuts and processed fractions using stable isotopes

Syed Abdul Wadood; Jing Nie; Chunlin Li; Karyne M Rogers; Yongzhi Zhang; Yuwei Yuan

doi:10.1016/j.fochx.2022.100456

Geographical origin classification of peanuts and processed fractions using stable isotopes

Food Chem X. 2022 Sep 26:16:100456. doi: 10.1016/j.fochx.2022.100456. eCollection 2022 Dec 30.

Authors

Syed Abdul Wadood^{1

2

3}, Jing Nie^{1

3}, Chunlin Li^{1

3}, Karyne M Rogers^{1

3

4}, Yongzhi Zhang³, Yuwei Yuan^{1

3}

Affiliations

¹ Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Key Laboratory of Information Traceability for Agricultural Products, Ministry of Agriculture and Rural Affairs of China, Hangzhou 310021, China.
² Department of Nutrition & Health Promotion, University of Home Economics Lahore, Pakistan.
³ State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Hangzhou 310021, China.
⁴ National Isotope Centre, GNS Science, 30 Gracefield Road, Lower Hutt 5040, New Zealand.

Abstract

This study investigates the use of stable isotopes (C, N, H, and O) to characterize the geographical origin of peanuts along with different peanut fractions including whole peanut kernel, peanut shell, delipidized peanuts and peanut oil. Peanut samples were procured in 2017 from three distinctive growing regions (Shandong, Jilin, and Jiangsu) in China. Peanut processing significantly influenced the δ ¹³C, δ ²H, and δ ¹⁸O values of different peanut fractions, whereas δ ¹⁵N values were consistent across all fractions and unaffected by peanut processing. Geographical differences of peanut kernels and associated peanut fractions showed a maximum variance for δ ¹⁵N and δ ¹⁸O values which indicated their strong potential to discriminate origin. Different geographical classification models (SVM, LDA, and k-NN) were tested for peanut kernels and associated peanut fractions. LDA achieved the highest classification percentage, both on the training and validation sets. Delipidized peanuts had the best classification rate compared to the other fractions.

Keywords: Chemometrics; Geographical origin; Peanut (Arachis hypogaea L.); Processing; Stable isotopes.