Effects of Starter Culture and Storage on the Flavor of Liquid Whey

Abstract

Lipid oxidation products are primary contributors to whey ingredient off-flavors. Flavor plays a critical and limiting role in widespread use of dried whey ingredients, and enhanced understanding of flavor and flavor formation in fluid whey are industrially relevant. Results from this study demonstrate that oxidation occurs in milk prior to cheesemaking but that starter type and starter strain influence also oxidative stability and lipid oxidation off flavors in fluid whey.

Comparison of the Flavor Chemistry and Flavor Stability of Mozzarella and Cheddar Wheys

“…Attributes were scored using a 0‐ to 15‐point universal Spectrum™ intensity scale where 0 = absence of the attribute and 15 = extremely high intensity of attribute. Most whey protein flavors fall between 0 and 4 (Campbell and others 2011a, 2011b). LSD = least significant difference. …”

“…Karagul‐Yuceer and others (2003) identified aroma‐active compounds in liquid Cheddar wheys including 2,3‐butanedione, 2‐butanol, hexanal, 2‐acetyl‐1‐pyrroline, methional, ( E,E )‐2,4‐nonadienal, ( E,E )‐2,4‐decadienal, and other short‐chain volatile acids. Campbell and others (2011b) documented differences in volatile compound profiles of Cheddar wheys from different mesophilic starter cultures and also demonstrated that higher concentrations of lipid oxidation products were noted in Cheddar whey compared to Mozzarella whey. Gallardo‐Escamilla and others (2005) evaluated several different types of liquid whey by sensory and headspace analysis but did not identify the distinguishing aroma‐active compounds.…”

“…The temperature of the cold milk was raised to 31 or 35 °C (Cheddar or Mozzarella, respectively) with gentle stirring. Once the milk reached 31 or 35 °C, Cheddar or Mozzarella cheese was manufactured as described by Campbell and others (2011b). For Cheddar cheese: freeze‐dried starter culture of Lactococcus lactis ssp.…”

“…Sensory testing was conducted in compliance with NCSU Institutional Review Board (IRB) for human subjects approval. A trained sensory panel ( n = 10, 7 females, 3 males, aged 22 to 37 y) evaluated the flavor attributes of the liquid whey using a previously established lexicon for fluid whey (Campbell and others 2011b). Each panelist had over 150 h of experience with descriptive analysis of dried dairy ingredients, and additional training with liquid whey aroma and flavor.…”

“…Fourteen compounds, diacetyl, 2/3‐methylbutanal, acetic acid, hexanal, butanoic acid, Z ‐4‐heptenal, heptanal, 1‐octen‐3‐one, octanal, phenylacetaldehyde, nonanal, phenylethanol, E ‐2‐nonenal, decanal, E,E ‐2,4‐nonadienal, were selected for quantification due to their different polarities and because current AEDA results as well as previous studies suggested that these compounds were important in whey flavor or flavor stability (Carunchia Whetstine and others 2003; Campbell and others 2011a, 2011b). Concentrations of selected compounds were calculated using a 5‐point standard curve (minimum R 2 > 0.92).…”