TY - JOUR

T1 - Exploring process dynamics by near infrared spectroscopy in lactic fermentations

AU - Svendsen, Carina

AU - Cieplak, Tomasz

AU - van der Berg, Franciscus Winfried J

PY - 2016

Y1 - 2016

N2 - In the industrial production of yoghurt, measurement of pH is normally the only in-line technique applied as a real-time monitoring signalfor following the dynamics during the fermentation process. However, every dairy company would benefit from an in-line technique giving information about the chemical composition, physical/textural properties and/or microbial contamination. In this study lactic fermentation batches with the starter bacteria Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus are explored by in-line near infrared (NIR) spectroscopy. The dynamics obtained from NIR spectroscopy is elucidated in order to explain what causes the variation of the indirect measurements. The results show that viscosity change has a large impact on the scatter, which affects the NIR data. It seems that the variation found by NIR spectroscopy is caused by both scatter and absorption, where the scatter gives us information about the textural change happening, and the absorption gives us information about the biomass formation plus the conversion of sugar into lactic acid.

AB - In the industrial production of yoghurt, measurement of pH is normally the only in-line technique applied as a real-time monitoring signalfor following the dynamics during the fermentation process. However, every dairy company would benefit from an in-line technique giving information about the chemical composition, physical/textural properties and/or microbial contamination. In this study lactic fermentation batches with the starter bacteria Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus are explored by in-line near infrared (NIR) spectroscopy. The dynamics obtained from NIR spectroscopy is elucidated in order to explain what causes the variation of the indirect measurements. The results show that viscosity change has a large impact on the scatter, which affects the NIR data. It seems that the variation found by NIR spectroscopy is caused by both scatter and absorption, where the scatter gives us information about the textural change happening, and the absorption gives us information about the biomass formation plus the conversion of sugar into lactic acid.

KW - Fermentation

KW - Growth associations

KW - In-line measurements

KW - Lactobacillus delbrueckii subsp. dynamics

KW - Monitoring

KW - Near infrared spectroscopy

KW - Streptococcus thermophilus

KW - Yoghurt

U2 - 10.1255/jnirs.1244

DO - 10.1255/jnirs.1244

M3 - Journal article

AN - SCOPUS:84994184697

VL - 24

SP - 443

EP - 451

JO - Journal of Near Infrared Spectroscopy

JF - Journal of Near Infrared Spectroscopy

SN - 0967-0335

IS - 5

ER -