Estimation of Ascorbic Acid in Intact Acerola (Malpighia emarginata DC) Fruit by NIRS and Chemometric Analysis

Francisca Moraes,Fábio Medeiros,Camilo Morais,Rosangela Costa,Tássia Fernandes,Kássio Lima,Roberta Hoskin

doi:10.3390/horticulturae5010012

Francisca Moraes, Fábio Medeiros + Show 5 more

Open Access

https://doi.org/10.3390/horticulturae5010012

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Abstract

Acerola fruit is one of the richest natural sources of ascorbic acid ever known. As a consequence, acerola fruit and its products are demanded worldwide for the production of health supplements and the development of functional products. However, the analytical determination of ascorbic acid is time-consuming and costly. In this study, we show a non-destructive, reliable, and fast method to measure the ascorbic acid content in intact acerola, using near-infrared spectroscopy (NIRS) associated with multivariate calibration methods. Models using variable selection by means of interval partial least squares (iPLS) and a genetic algorithm (GA) were tested. The best model for ascorbic acid content, based on the prediction performance, was the GA-PLS method with second derivative spectral pretreatment, with a root mean square error of cross-validation equal to 22.9 mg/100 g, root mean square error of prediction equal to 46.3 mg/100 g, ratio of prediction to deviation equal to 8.0, determination coefficient for calibration equal to 0.98 and determination coefficient for prediction equal to 0.96. The current methodology, using NIR spectroscopy and chemometrics, is a promising and rapid tool to determine the ascorbic acid content of intact acerola fruit.

Highlights

Acerola (Malpighia emarginata DC.), called the Barbados cherry or cherry-of-Antilles, has its origin traced to the Caribbean area, northern South America and Central America
It has been already shown that ascorbic acid is greatly reduced from the green to the ripe stage of acerola fruit due to biochemical oxidation reactions related to maturation [24]
A method based on near-infrared spectroscopy (NIRS) and multivariate calibration was developed to estimate the ascorbic acid content of intact acerola fruit

Summary

Introduction

Acerola (Malpighia emarginata DC.), called the Barbados cherry or cherry-of-Antilles, has its origin traced to the Caribbean area, northern South America and Central America. This tropical fruit is known for its high concentration of health-relevant phytochemicals, mainly ascorbic acid [1]. The uniquely high concentration of ascorbic acid makes this fruit valuable for further use in other food products and creates a great potential market for acerola. Significant market growth is expected for acerola extract. The global acerola extract market is expected to be worth 17.5 billion US dollars by. 2026, due to rising global demand for natural bioactive-rich fruits and derivatives, such as acerola [2,3].

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