Evaluation of Carrot Quality Using Visible-Near Infrared Spectroscopy and Multivariate Analysis

Ahmed Rady,Shinta Sugiharto,Akinboe Adedeji

doi:10.5539/jfr.v7n4p80

Abstract

Carrot has a relatively high content of Vitamin C and it is a major source of natural carotenoids. However, carrot has a short shelf-life and is better consumed fresh. A quick assessment of its quality attributes is important to preserving its freshness. The objective of this study was to apply Vis-NIR spectroscopy to noninvasively assess and predict the various quality attributes of carrot (cv. Nectar), namely color (L*a*b*), moisture content (MC), total soluble solids (TSS), firmness, Vitamin C, and β-carotene. Two spectroscopic sensors (400-1,000 nm and 900-1,700 nm) were utilized and samples included whole root and 25.4 mm thick sliced disc. The best prediction models using partial least squares regression yielded correlation coefficient, r, and ratio of performance to deviation or r(RPD) of 0.50(0.73), 0.84(0.88), 0.86(2.07), 0.69(0.66), 0.97(1.44), 0.90(1.49), 0.47(1.47), and 0.92(1.76) for color indices, L* a* b*, firmness, MC, TSS, Vitamin C, and β-carotene, respectively. However, using only the wavelengths selected by interval partial least squares, the r(RPD) values for the aforementioned attributes improved and are presented as follows: 0.92(1.97), 0.96(2.83), 0.98(5.85), 0.99(6.65), 0.98(3.91), 0.99(5.93), 0.98(4.16), and 0.98(4.43), respectively. Generally, Vis-NIR region had higher prediction performance than NIR region, and whole roots had similar prediction performance as sliced samples. This study shows that rapid determination of quality parameters of carrot is possible through non-destructive Vis-NIR sensing, which could be useful for quality tracking during carrot supply chain. Moreover, results of this study could be improved using a larger sample size.

Highlights

Carrot (Daucus carota L.) is an important root vegetable crop and a major source of essential micronutrients such as Vitamins A and C
The wavelengths implemented in such study had close value to those obtained in the current study using interval partial least squares (IPLS)
In this study, several quality characteristics of carrot roots were evaluated using spectroscopic data obtained from Vis-NIR and NIR sensors

Summary

Introduction

Carrot (Daucus carota L.) is an important root vegetable crop and a major source of essential micronutrients such as Vitamins A and C. Carrot is a rich source of provitamin A and α and β-carotene and carotenoids (lutein, lycopene) depending on the root color (Berger, Küchler, Maaßen, Busch-Stockfisch, & Steinhart, 2008). The production of α-tocopherol-β-carotene (ATBC) drinks, called carotenoid drinks, depends on carrot juice as a natural source of provitamin A (Simon et al, 2008; Demir, Acar, & Bahçeci, 2004). Quality attributes of carrots that are important indicators of stability and support systems for human health include absence of bruises, color, total soluble solid (TSS), provitamin A especially β-carotene and carotenoids, Vitamin C, and firmness (Simon et al, 2008; Demir et al, 2004).

Objectives

Methods

Results

Conclusion