Effect of γ-Aminobutyric Acid-enriched Tempeh-like Fermented Soybean (GABA-Tempeh) on the Blood Pressure of Spontaneously Hypertensive Rats

GABA-enriched tempeh-like fermented soybean (GABA-tempeh) was supplemented to the AIN-76 diet and fed for 2 months to spontaneously hypertensive rats (SHRs), an animal model of spontaneously developed hypertension, to compare the antihypertensive activity with that of authentic GABA. The elevation of systolic blood pressure in SHRs was significantly retarded in the GABA-tempeh group as well as that with authentic GABA when compared with the controls, and the effect lasted for two months of the feeding period. The blood urea nitrogen level tended to be higher in the control group than in the GABA-supplemented groups. On the other hand, no effect was apparent on the plasma levels of cholesterol, triacylglycerol and glucose, or on the urinary excretion of Na and K.     

The Fibrinolytic Activity of a Novel Protease Derived from a Tempeh Producing Fungus,Fusarium sp. BLB

Tempeh is a traditional Indonesian soybean-fermented food produced by filamentous fungi, Rhizopus sp. and Fusarium sp. We isolated and sequenced the genomic gene and a cDNA clone encoding a novel protease (FP) from Fusarium sp. BLB. The genomic gene was 856 bp in length and contained two introns. An isolated cDNA clone encoded a protein of 250 amino acids. The predicted amino acid sequence of FP showed highest homology, of 76%, with that of trypsin from Fusarium oxysporum. The hydrolysis activity of FP toward synthetic peptide was higher than that of any other protease tested, including Nattokinases. Furthermore, the thrombolytic activity of FP was about 2.1-fold higher than that of Nattokinase when the concentration of plasminogen was 24 units/ml. These results suggest that FP is superior to Nattokinases in dissolving fibrin when absorbed into the blood.     

Image analysis for monitoring the barley tempeh fermentation process

AIMS: To develop a fast, accurate, objective and nondestructive method for monitoring barley tempeh fermentation. METHODS AND 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. CONCLUSION: 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. SIGNIFICANCE AND IMPACT OF THE STUDY: 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.