Effect Of Various Bacteria On The Flavor Of Cheddar Cheese Made From Pasteurized Milk

Author : Gregory S. Turbes
Publisher :
ISBN 13 :
Total Pages : 145 pages
Book Rating : 4.:/5 (891 download)

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Download or read book Impact of Terroir on Cheddar Cheese Flavor and the Influence of Farm-to-farm Variability, Commingling, and Pasteurization written by Gregory S. Turbes and published by . This book was released on 2014 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: The concept of terroir is commonly used as marketing tool to highlight unique characteristics of regional food products, however there is little scientific evidence of terroir pertaining to cheese. The purpose of this research was to investigate the potential impact of milk origin, pasteurization, and commingling on the sensorial, chemical, and bacterial variabilities in Cheddar cheese. Milk was collected from single farms and commingled sites from geographically distinct regions around Oregon in early Fall, 2013. Milk was transported to the Arbuthnot Dairy Center on the Oregon State University campus and made into raw- milk and pasteurized-milk Cheddar cheese. At 5 months and 9 months into aging cheeses were submitted to consumer sensory testing, volatile compound analysis, and non-starter lactic acid bacteria enumeration and identification. Cheeses were evaluated to determine if consumers could perceive flavor differences. Frequent Cheddar cheese consumers were asked to sort the cheeses based on perceived flavor similarity. Results at 5 months into aging revealed that geographic location of the milk origin impacted the flavor of the cheeses. Furthermore, commingling of milk appeared to mitigate the effect of location. Testing at 9 months into aging showed that pasteurization had the greatest impact on cheese flavor, resulting in raw cheeses with a more "intense" flavor than their pasteurized counterparts. Volatile compounds were investigated using headspace-solid phase microextraction-gas chromatography-mass spectrometry. At 5 months into aging, the volatile compound profiles of the cheeses varied based upon each collection location. The thermal treatment applied to the milk did not appear to have a large impact on the volatiles detected. Volatile compound compositions at 9 months into aging showed differences between each location. There was a clear disparity between the raw milk cheeses and pasteurized milk cheeses within the milk sourcing locations. Non-starter lactic acid bacteria, specifically lactobacilli, were investigated due to their contribution to flavor generation in Cheddar cheese. Identification and enumeration at 5 months exposed that raw and pasteurized cheeses were dominated by Lb. paracasei and Lb. plantarum, respectively. Biochemical characterization within the species revealed large diversity across sampling locations. The data presented indicates that milk origin has an impact on Cheddar cheese flavor. There was agreement between consumer perceptions of cheeses with the detected volatile compound profiles. Non-starter lactic acid bacteria identification in the cheese may give insight into the causation of the flavor differentiations. The research can help local cheese producers differentiate their products in the marketplace and demonstrate the importance of regional milk sourcing for national cheese companies sourcing milk from different locations.