Submitted to: Small Ruminant Research
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/6/2006
Publication Date: 5/3/2006
Citation: Olson, D.W., Van Hekken, D.L., Tunick, M.H., Soryal, K.A., Zeng, S.S. 2007 Effects of aging on functional properties of caprine milk made into cheddar- and colby-like cheeses. Small Ruminant Research. 70:218-227. Interpretive Summary: Cheeses made from goats' milk are becoming more popular in the United States, yet little information is available for Cheddar-like and Colby-like cheeses made from goats' milk. Goats in many herds typically begin milking in the Spring and milk for about 24 wk. The composition of the milk is known to change over this milking cycle but how this affects the cheese properties is not well known. The effects of milk (used to make the cheese) collected during different parts of the milking cycle (beginning, middle, and end) and the effects of cheese aging on color change upon heating (browning), melting, and the force required to cut the cheeses were studied. Milking cycle influenced the extent of browning and the required cutting force differently for Cheddar-like cheese than for Colby-like cheese, but did not affect meltability. As the cheeses became older, they underwent different degrees of browning, melted more, and became easier to slice. Differences in extent of browning, melting, and required cutting force were often related to the amount of protein breakdown in the cheeses. By understanding the effects of milking cycle and cheese aging on the properties of cheese, goats' milk cheesemakers can improve the quality of the cheeses.
Technical Abstract: The effects of cheesemilk obtained at each stage of lactation (early, peak, and late) and cheese storage (up to 16 or 24 wk) on color changes upon heating (232 deg C for 5 min or 130 deg C for 75 min), meltability, and sliceability (force required to cut through the cheese) of goats' milk cheeses were evaluated. The cheeses were manufactured from Alpine goats' milk and based on the procedures used to make Cheddar and Colby cheeses from cows' milk. The stage of lactation of the cheesemilk affected the total color change upon heating (browning) in Cheddar-like cheese (peak and late > early for both heat treatments) and in Colby-like cheese (peak > early > late for the 130 deg C min heat treatment and late > early for the 232 deg C heat treatment) but did not affect the meltability of either cheese. Greater cutting forces were required when Cheddar-like cheese and young (less than 1 wk old) Colby-like cheese were made from peak lactation milk instead of late lactation milk. Although aging had a variable effect on the total color change upon heating, meltability increased and the force required to slice the cheeses decreased with aging. These changes with aging were highly correlated with proteolysis occurring during storage. Cheesemilk obtained at different lactation stages and aging of the cheese impacts the functional properties of goats' milk cheeses and will affect their optimal utilization.