Real time and in situ Near-Infrared Spectroscopy (Nirs) for Quantitative Monitoring of Biomass, Glucose, Ethanol and Glycerine concentrations in an alcoholic fermentation

Abstract

-This study investigates the application of NIR spectroscopy for real-time monitoring of process parameters in alcoholic fermentations. For this purpose, fermentation batches using Saccharomyces cerevisiae were carried out and monitored in situ by an immersed NIRS probe. Samples were collected throughout the fermentations, and concentrations of biomass, glucose, ethanol and glycerin were analyzed by reference methods and multivariate data analyses such as PCA and PLSR. PCA was used to investigate data variability and to select samples for calibration and for external validation sets. A PLSR model for biomass yielded R 2 and RMSEP values of 0.99 and 0.276 g.L -1 , respectively. For glucose, the carbon source, the PLSR model yielded an R 2 of 0.95 and an RMSEP of 7.14 g.L -1 . The PLSR model for ethanol was characterized by an R 2 of 0.95 and an RMSEP of 0.06 g.L -1 . For glycerin, a highly accurate PLSR model with an R 2 of 0.98 and an RMSEP of 0.116 g.L-1 was obtained. These results indicate that an in situ NIRS probe is suitable for real-time monitoring of important parameters in alcoholic fermentations.

Real‐time monitoring of ethanol production during Pichia stipitis NRRL Y‐7124 alcoholic fermentation using transflection near infrared spectroscopy

“…Substrate consumption shows two critical points of interest. In a previous study [16], validated models for real time prediction were also applied obtaining satisfying results, despite less accurate predictions, probably for two situations. In this case biomass, glucose and xylose are involved ( Fig.…”

“…Miguel A. de Quevedo 2779, Col. Formando Hogar, CP 91860, Veracruz, México Abbreviation: %e, error percentage; MSC, multiplicative scattering correction; NIR, near-infrared; NIRS, near-infrared spectroscopy; PLSR, partial least square regression; VIP, variable influence in the projection of several advantages [1]; however, a major drawback of this species is that it cannot metabolize xylose [2], the most common sugar in hemicellulose and which represents a sizable fraction of lignocellulosic materials. Hence, near infrared spectroscopy (NIRS) can be applied as a real-time fermentation monitoring methodology using multiconstituent, rapid and nondestructive analyses, without involving sample pretreatment that leads to effective bioprocess control, a tool for increased yield, productivity, and reproducibility [14][15][16]. Nevertheless, the use of yeasts such as Pichia stipitis, naturally capable of metabolizing hexoses and pentoses, is a feasible solution for ethanol production from these renewable resources.…”

“…Development and bioprocess optimization are highly dependent on accurate real-time monitoring of chemical and physical process variables [11][12][13]. Hence, near infrared spectroscopy (NIRS) can be applied as a real-time fermentation monitoring methodology using multiconstituent, rapid and nondestructive analyses, without involving sample pretreatment that leads to effective bioprocess control, a tool for increased yield, productivity, and reproducibility [14][15][16]. In the present study, the utility of NIRS for real-time monitoring of alcoholic fermentation by P. stipitis NRRL Y-7124, using glucose and xylose as a carbon source and the use of chemometric tools and plots for understanding the process, was investigated.…”

Application of green analytical chemistry to a green chemistry process: Magnetic resonance and Raman spectroscopic process monitoring of continuous ethanolic fermentation

“…The goals of GAC is resource‐ and energy‐saving for analytical methods, too. Analyses should hence be operated in automation and at the same time be able to furnish as many parameters as possible requiring only a very little amount of sample or sample volume (Nascimento, Macedo, Santos, & Oliveira, ; Schalk et al, ; Villar et al, ). The use of spectroscopic methods enables the monitoring of all relevant process media in real time.…”

Rapid detection model of Bacillus subtilis in solid‐state fermentation of rapeseed meal

“…NIR spectroscopy is widely used in the fermentation, food, agricultural, petrochemical and pharmacological industries due to its rapid, noninvasive and economic advantages (H. Jiang et al, ; Tong, Du, Zheng, Wu, & Wang, ). In their study, do Nascimento, de Macedo, dos Santos, and de Oliveira () reported that NIRS can be utilized for actual‐time detecting of process factors in alcoholic fermentation. Andueza, Agabriel, Constant, Lucas, and Martin () used NIRS to achieve the ordering of cheese samples from various regimes.…”