Spectroscopic Profiling Combining Chemometric Analysis of Nutritional and Chemical Changes in Tempeh During Rendang Preparation

Rendang tempeh is a plant-based protein food product made primarily from fresh tempeh. The production process involves several stages, including transforming fresh tempeh into gulai tempeh, kalio tempeh, and finally rendang tempeh. This study aimed to observe and analyze each stage of the rendang tempeh production process to identify and quantify key compounds, such as amino acids, fatty acids, and polyphenols. A chemometric approach was applied using Fourier transform infrared spectroscopy (FTIR) and headspace gas chromatography–mass spectrometry (HS GC-MS) to predict changes in chemical composition and nutritional compounds across processing stages. Proximate analysis revealed that the highest moisture content was found in the gulai tempeh stage (۶۳.۴۳%), the highest ash content in the rendang tempeh stage (۴.۳۸%), the highest fat content also in the rendang tempeh stage (۳۴.۶۴%), and the highest protein content in fresh tempeh (۱۹.۸۸%). FTIR analysis indicated similarities in IR absorption across stages, with differences in % transmittance and functional group variations, notably the absence of specific bands in fresh tempeh within the ۱,۸۰۰–۲,۳۴۵ cm⁻¹ wavelength range. HS GC-MS analysis identified several volatile compounds at each stage, including ۳-methylbutanal, pentanal, and hexanal. This research provides valuable insights into the chemical and nutritional transformations during the production of rendang tempeh and offers a foundation for optimizing the quality of tempeh-based processed products.

کلیدواژه ها:

Tempeh ، Gulai ، Kalio ، Rendang ، chemometrics