title: Quality Evaluation of Shelled and Unshelled Macadamia Nuts by Means of Near-Infrared Spectroscopy (NIR).
abstract: The quality of shelled and unshelled macadamia nuts was assessed by means of Fourier transformed near-infrared (FT-NIR) spectroscopy. Shelled macadamia nuts were sorted as sound nuts; nuts infected by Ecdytolopha aurantiana and Leucopteara coffeella; and cracked nuts caused by germination. Unshelled nuts were sorted as intact nuts (<10% half nuts, 2014); half nuts (March, 2013; November, 2013); and crushed nuts (2014). Peroxide value (PV) and acidity index (AI) were determined according to AOAC. PCA-LDA shelled macadamia nuts classification resulted in 93.2% accurate classification. PLS PV prediction model resulted in a square error of prediction (SEP) of 3.45 meq/kg, and a prediction coefficient determination value (Rp (2) ) of 0.72. The AI PLS prediction model was better (SEP = 0.14%, Rp (2) = 0.80). Although adequate classification was possible (93.2%), shelled nuts must not contain live insects, therefore the classification accuracy was not satisfactory. FT-NIR spectroscopy can be successfully used to predict PV and AI in unshelled macadamia nuts, though.
authors.affiliation: Dipt. di Agraria, Univ. degli Studi di Sassari, Via Enrico de Nicola, 7, 07.100, Sassari, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Canneddu
authors.affiliation: Univ. Federal de Goiás (UFG), Escola de Agronomia (EA), Setor de Horticultura. Avenida Esperança s/n - Campus Universitário, 74.690-000, Goiânia, GO, Brazil.
authors.forename: Luis Carlos Cunha
authors.initials: LC
authors.lastname: Júnior
authors.affiliation: Univ. Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias (FCAV), Via de acesso Prof. Paulo Donato Castellane s/n, 14.870-900, Jaboticabal, SP, Brazil.
authors.forename: Gustavo Henrique
authors.initials: GH
authors.lastname: de Almeida Teixeira
mesh_terms: D000143:Acids / Q000032:analysis*; D000818:Animals; D005504:Food Analysis / Q000379:methods; D018525:Germination; D006801:Humans; D007313:Insecta; D015227:Lipid Peroxidation; D039106:Macadamia; D009754:Nuts / Q000737:chemistry / Q000145:classification / Q000592:standards*; D010545:Peroxides / Q000032:analysis*; D019265:Spectroscopy, Near-Infrared / Q000379:methods*
chemical_list: D000143:Acids; D010545:Peroxides
keywords: Ecdytolopha aurantiana; LDA; Leucopteara coffeella; Macadamia integrifolia Maiden & Betche; PCA; PLS; PLS-DA; acidity index; peroxide value