title: Image analysis for monitoring the barley tempeh fermentation process.
abstract: OBJECTIVE
  To develop a fast, accurate, objective and nondestructive method for monitoring barley tempeh fermentation.
  
  
  RESULTS
  Barley tempeh is a food made from pearled barley grains fermented with Rhizopus oligosporus. Rhizopus oligosporus growth is important for tempeh quality, but quantifying its growth is difficult and laborious. A system was developed for analysing digital images of fermentation stages using two image processing methods. The first employed statistical measures sensitive to image colour and surface structure, and these statistical measures were highly correlated (r=0.92, n=75, P<0.001) with ergosterol content of tempeh fermented with R. oligosporus and lactic acid bacteria (LAB). In the second method, an image-processing algorithm optimized to changes in images of final tempeh products was developed to measure number of visible barley grains. A threshold of 5 visible grains per Petri dish indicated complete tempeh fermentation. When images of tempeh cakes fermented with different inoculation levels of R. oligosporus were analysed the results from the two image processing methods were in good agreement.
  
  
  CONCLUSIONS
  Image processing proved suitable for monitoring barley tempeh fermentation. The method avoids sampling, is nonintrusive, and only requires a digital camera with good resolution and image analysis software.
  
  
  CONCLUSIONS
  The system provides a rapid visualization of tempeh product maturation and qualities during fermentation. Automated online monitoring of tempeh fermentation by coupling automated image acquisition with image processing software could be further developed for process control.
authors: Department of Microbiology, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden. Xinmei.feng@mikrob.slu.se
authors: X M
authors: XM
authors: Feng
authors: J
authors: J
authors: Olsson
authors: M
authors: M
authors: Swanberg
authors: J
authors: J
authors: Schnürer
authors: D
authors: D
authors: Rönnow
mesh_terms: D003116:Color; D004875:Ergosterol / Q000378:metabolism; D005285:Fermentation; D005511:Food Handling / Q000379:methods; D005516:Food Microbiology; D001467:Hordeum / Q000378:metabolism / Q000382:microbiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D052197:Limosilactobacillus fermentum / Q000502:physiology; D012233:Rhizopus / Q000254:growth & development / Q000502:physiology*; D013172:Spores, Fungal / Q000502:physiology; D013499:Surface Properties
chemical_list: D004875:Ergosterol