Feasibility Study on The Use of UV/Vis Spectroscopy to Measure Total Phenolic Compound (TPC) and pH in Apple (Malus Sylvestris L) Combined with Chemomectrics Analysis
Z Iqbal1, A N Komariyah2, I P Adiyaksa1, B D Argo2, Y Wibisono2, M A Kamal3, R Damayanti1
1Department of Agricultural Engineering, Universitas Brawijaya, Malang, Indonesia
2Department of Bioprocess Engineering, Universitas Brawijaya, Malang, Indonesia
3Department of Agro-industrial Technology, Universitas Brawijaya, Malang, Indonesia
Abstract
Apple (Malus sylvestris L) is one of important crops cultivated as a raw material to produce typical product from Malang City such as, apple drink and chip. In order to produce a good quality product, a uniform ripeness level of apple need to be attained. As a traditional method, the farmer and industrial worker only sorted the raw material based on its physical properties, i.e. size and colour, which depend on their decision that may lead to non-standard result. Thus, to address this issue, a rapid and quantitative measurement such as UV/Vis spectroscopy need to be developed. The aim of this research is to study the feasibility on the use of UV/Vis spectroscopy to determine apple quality based on its chemical compound. To achieved the conclusion, several stages had to be conducted. First, the total 60 sample of apples from 4 different ripening stages (3, 4, 5 and 6 month) were collected from local farmer in Bumiaji District and extracted. The juice from extraction was prepared for UV/Vis spectrum collection ranging from 340-800nm. Then, the Total Phenolic Compound (TPC) and pH were measured. Second, performing chemometric analysis to provide Partial Least Square (PLS) prediction model. And the third was identifying robustness of the model by analysing all the statistic parameter. The result showed that, PLS model to predict pH provided good determination coefficient (r2) resulting 0.9142 while RPD, LV and RSMEP accounting for 1.98, 6, and 0.0466 respectively. Meanwhile, the TPC could not be predicted well by using this regression.
Keywords: Apple, checomectric, quantitative measurement, UV/Vis spectroscopy
Topic: AGRICULTURAL ENGINEERING