Institute of Bioengineering and Process Control, Department of Measurements and Process Control, Faculty of Food Science, Szent István University, 1118 Budapest, Hungary.
Sensors (Basel). 2021 Jan 17;21(2):611. doi: 10.3390/s21020611.
Mung bean is a leguminous crop with specific trait in its diet, namely in the form of anti-nutrient components. The sprouting process is commonly done for better nutritional acceptance of mung bean as it presents better nutritional benefits. Sprouted mung bean serves as a cheap source of protein and ascorbic acid, which are dependent on the sprouting process, hence the importance of following the biological process. In larger production scale, there has not been a definite standard for mung bean sprouting, raising the need for quick and effective mung bean sprout quality checks. In this regard, near-infrared spectroscopy (NIRS) has been recognized as a highly sensitive technique for quality control that seems suitable for this study. The aim of this paper was to describe quality parameters (water content, pH, conductivity, and ascorbic acid by titration) during sprouting using conventional analytical methods and advanced NIRS techniques as correlative methods for modelling sprouted mung beans' quality and ascorbic acid content. Mung beans were sprouted in 6 h intervals up to 120 h and analyzed using conventional methods and a NIR instrument. The results of the standard analytical methods were analyzed with univariate statistics (analysis of variance (ANOVA)), and the NIRS spectral data was assessed with the chemometrics approach (principal component analysis (PCA), discriminant analysis (DA), and partial least squares regression (PLSR)). Water content showed a monotonous increase during the 120 h of sprouting. The change in pH and conductivity did not describe a clear pattern during the sprouting, confirming the complexity of the biological process. Spectral data-based discriminant analysis was able to distinctly classify the bean sprouts with 100% prediction accuracy. A NIRS-based model for ascorbic acid determination was made using standard ascorbic acid to quantify the components in the bean extract. A rapid detection technique within sub-percent level was developed for mung bean ascorbic acid content with R above 0.90. The NIR-based prediction offers reliable estimation of mung bean sprout quality.
绿豆是一种豆科作物，其饮食具有特殊特性，即存在抗营养成分。发芽过程通常是为了更好地接受绿豆的营养，因为它具有更好的营养价值。发芽的绿豆是廉价的蛋白质和抗坏血酸来源，这取决于发芽过程，因此遵循生物过程非常重要。在大规模生产中，绿豆发芽还没有明确的标准，这就需要快速有效的绿豆芽质量检查。在这方面，近红外光谱（NIRS）已被公认为一种高度敏感的质量控制技术，似乎适合本研究。本文的目的是描述发芽过程中的质量参数（水分含量、pH 值、电导率和滴定法测定的抗坏血酸），使用常规分析方法和先进的 NIRS 技术作为相关方法，对发芽绿豆的质量和抗坏血酸含量进行建模。绿豆在 6 小时的间隔内发芽至 120 小时，并用常规方法和 NIR 仪器进行分析。用单变量统计（方差分析（ANOVA））分析标准分析方法的结果，并采用化学计量学方法（主成分分析（PCA）、判别分析（DA）和偏最小二乘回归（PLSR））评估 NIRS 光谱数据。水分含量在 120 小时的发芽过程中呈单调增加。pH 值和电导率的变化在发芽过程中没有描述出明显的模式，这证实了生物过程的复杂性。基于光谱数据的判别分析能够以 100%的预测精度清晰地区分豆芽。使用标准抗坏血酸建立了基于 NIRS 的抗坏血酸测定模型，以定量测定豆提取物中的成分。开发了一种用于绿豆抗坏血酸含量的快速检测技术，其亚百分含量的检测精度高，R 值大于 0.90。基于 NIR 的预测能够可靠估计绿豆芽的质量。
