Quantification of Water, Protein and Soluble Sugar in Mulberry Leaves Using a Handheld Near-Infrared Spectrometer and Multivariate Analysis.

Yue Ma,Guo-Zheng Zhang,Sedjoah Aye-Ayire Rita-Cindy

doi:10.3390/molecules24244439

Abstract

Mulberry (Morus alba L.) leaves are not only used as the main feed for silkworms (Bombyx mori) but also as an added feed for livestock and poultry. In order to rapidly select high-quality mulberry leaves, a hand-held near-infrared (NIR) spectrometer combined with partial least squares (PLS) regression and wavelength optimization methods were used to establish a predictive model for the quantitative determination of water content in fresh mulberry leaves, as well as crude protein and soluble sugar in dried mulberry leaves. For the water content in fresh mulberry leaves, the R-square of the calibration set (), R-square of the cross-validation set () and R-square of the prediction set () are 0.93, 0.90 and 0.91, respectively, the corresponding root mean square error of calibration set (RMSEC), root mean square error of cross-validation set (RMSECV) and root mean square error of prediction set (RMSEP) are 0.96%, 1.13%, and 1.18%, respectively. The , and of the crude protein prediction model are 0.91, 0.83 and 0.92, respectively, and the corresponding RMSEC, RMSECV and RMSEP are 0.71%, 0.97% and 0.61%, respectively. The soluble sugar prediction model has , , and of 0.64, 0.51, and 0.71, respectively, and the corresponding RMSEC, RMSECV, and RMSEP are 2.33%, 2.73%, and 2.36%, respectively. Therefore, the use of handheld NIR spectrometers combined with wavelength optimization can fastly detect the water content in fresh mulberry leaves and crude protein in dried mulberry leaves. However, it is a slightly lower predictive performance for soluble sugar in mulberry leaves.

Highlights

Mulberry is a perennial root plant, and the leaves contain a variety of nutrients, such as proteins, soluble sugars, and fat, which are essential nutrients for the growth and development of silkworm [1].The amino acids in mulberry leaves are abundant and suitable in proportion, and the essential and semi-essential amino acids account for more than half of the total amino acids, with the contents of methionine and lysine higher than that of conventional feed
The raw NIR spectra of fresh mulberry leaves and dry mulberry leaves are shown in Figure 1, which shows that the primary trend of the spectral curves is similar
The statistics of water content, crude protein, and soluble sugar in mulberry leaves are shown in watercrude content, crudeand protein, and soluble sugar in leaves mulberry leaves are shown

Summary

Introduction

Mulberry is a perennial root plant, and the leaves contain a variety of nutrients, such as proteins, soluble sugars, and fat, which are essential nutrients for the growth and development of silkworm [1]. The amino acids (made up of proteins) in mulberry leaves are abundant and suitable in proportion, and the essential and semi-essential amino acids account for more than half of the total amino acids, with the contents of methionine and lysine higher than that of conventional feed. Mulberry leaves are palatable, highly digestible, and barrier-free feeding. They contain a variety of biologically active substances, which have effects on the improvement of immunity, anti-inflammatory, and anti-oxidant [2,3]. In the traditional sericulture industry, mulberry leaves are mainly used as feed for silkworms [4].

Methods

Results

Conclusion