title: Packaging modifications for protecting flavor of extended-shelf-life milk from light.
abstract: The effectiveness of titanium dioxide (TiO2)-loaded high-density polyethylene (HDPE) to reduce light-induced oxidation of extended-shelf-life milk (2% total fat) was studied. The objective was to determine differences over time in sensory quality, vitamin retention, and oxidative chemistry as a function of packaging and retail light exposure duration. Effectiveness of packaging for protecting milk quality was assessed by sensory evaluation (triangle tests, untrained panel), changes in volatile compounds, thiobarbituric reactive substances (TBARS), and riboflavin concentration. Milk (2%) was stored in HDPE packages consisting of TiO2 at 3 levels (low: 0.6%; medium: 1.3%; high: 4.3%) at 3 °C for up to 43 d. Light-protected (translucent, foil-wrapped) and light-exposed (translucent) HDPE packages served as controls. The high TiO2-HDPE package provided protection similar to light-protected control package through d 22 of light exposure, with less consistent performance by the medium TiO2 package. The TBARS increased in all treatments during storage. Under the experimental conditions used, a TBARS value of 1.3mg/L could be considered the limiting sensory threshold for differentiating oxidized milk from light-protected milk. Riboflavin concentration decreased 10.5% in the light-protected control and 28.5% in the high TiO2 packaged milk past 29 d of light exposure, but losses were greater than 40% for all other packages. The high TiO2 package protected riboflavin concentration from degradation and controlled aldehyde concentration throughout the test period.
authors: Department of Food Science and Technology, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg 24061.
authors: D S
authors: DS
authors: Johnson
authors: Department of Food Science and Technology, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg 24061. Electronic address: duncans@vt.edu.
authors: S E
authors: SE
authors: Duncan
authors: Department of Food Science and Technology, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg 24061.
authors: L M
authors: LM
authors: Bianchi
authors: Department of Food Science and Technology, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg 24061.
authors: H H
authors: HH
authors: Chang
authors: Department of Food Science and Technology, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg 24061.
authors: W N
authors: WN
authors: Eigel
authors: Department of Food Science and Technology, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg 24061.
authors: S F
authors: SF
authors: O'Keefe
mesh_terms: D000818:Animals; D004041:Dietary Fats / Q000032:analysis; D005511:Food Handling; D005516:Food Microbiology; D018857:Food Packaging / Q000379:methods*; D005519:Food Preservation / Q000379:methods*; D061353:Food Storage; D008401:Gas Chromatography-Mass Spectrometry; D008027:Light / Q000009:adverse effects*; D008892:Milk / Q000737:chemistry* / Q000382:microbiology; D010084:Oxidation-Reduction; D020959:Polyethylene / Q000737:chemistry; D011786:Quality Control; D012256:Riboflavin / Q000032:analysis; D013649:Taste; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D014025:Titanium / Q000737:chemistry; D055549:Volatile Organic Compounds
chemical_list: D004041:Dietary Fats; D017392:Thiobarbituric Acid Reactive Substances; D055549:Volatile Organic Compounds; C009495:titanium dioxide; D020959:Polyethylene; D014025:Titanium; D012256:Riboflavin
keywords: extended-shelf-life milk; oxidation; riboflavin; sensory