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<p>Objective 1: Characterization of the onset of damage from LED light: Time-intensity thresholds for the effects of fluorescent light have been determined for several foods, with consumers detecting differences in certain foods resulting from photo-oxidation after less than 2 hours of illumination. Modern point-of-sale locations are switching to LED light due to lower operational costs, but recommendations for exposure limits to avoid LED light-induced changes in flavor, color, or loss of photosensitive compounds (e.g. riboflavin, vitamin E) is still lacking. Hypothesis: Due to their inherent difference, a safe exposure time for food in LED lights exists but cannot be predicted from previous research on fluorescent lights.</p><p>Objective 2: Diagnosis of the associated sensory and chemical products formed by LED light exposure, when compared to fluorescent: Understanding the differences between LED and fluorescent light damage to foods requires quantitative study in both sensory and chemical domains. We will assay soybean oil and skim milk samples following light exposure by sensory, volatile, and nutritional analyses, to rationalize changes induced by differing light sources. Hypothesis: Volatile production patterns differ among light treatments (LED vs. fluorescent), and can be correlated to sensory off-aromas in exposed samples.</p><p>Objective 3: Intervention to determine conditions capable of preventing damage from LED illumination: In recent years, several advanced packaging materials have been demonstrated to protect in varying degrees from fluorescent light degradation. Likewise, antioxidant supplementation has proven somewhat effective in protecting against light damage in various foods. We will investigate the efficacy of active packaging, and antioxidant enrichment, in protecting both soybean oil and skim milk from LED light damage. Hypothesis: Optimal strategies for protecting food from LED photo-oxidation through the use of additives or active packaging will differ from optimal strategies previously developed for fluorescent light due to spectral differences between LED and fluorescent lighting. </p>
The primary driver of consumer preference for foods is flavor. Light damage is well-known to degrade food flavor and decrease consumer liking in a range of foodstuffs, often generating off-aroma compounds through degradation of proteins and lipids. Existing literature has investigated the chemosensory effects of light intensity, wavelength and duration of illumination on photooxidation - particularly for the fluorescent lighting common to retail locations, and often in combination with the initial properties of the food (ie protein/fat/vitamin/antioxidant content). These studies have led to recommendations for foodstuff storage to avoid quality loss. In recent years, LED display cases and overhead lighting have begun to replace conventional fluorescence lighting in retail markets, but little research exists to determine the potential of LED lights to damage foods, and whether knowledge derived from studies of fluorescent light and foodstuffs can be extrapolated to LEDs. My group has recently observed that LED and fluorescent light damage lead to off aromas that can be differentiated sensorially from those originating from fluorescence. The central hypothesis to this proposal is that photo-induced damage caused by modern LED lighting proceeds through a different pathways than for previously studied fluorescent lighting, resulting in altered off-aroma formation, thus necessitating different intervention strategies. We propose to investigate the conditions influencing LED light-induced degradation of foods in the modern marketplace, the mechanism responsible, and evaluate possible interventions, to safeguard food quality.Due to interest in energy and cost savings, retailers are increasingly replacing fluorescent bulbs with LED bulbs, but the consequences to food quality are not yet understood. The overarching goal of the study is to examine the effects of LED light damage on foods, and to assess available interventions to alleviate this damage. Our hypothesis is that photo-induced damage caused by modern LED lighting proceeds through a different pathways than for previously studied fluorescent lighting, resulting in altered off-aroma formation, thus necessitating different intervention strategies. Empirical recommendations for LED exposure limits will be developed using human sensory testing, color measurements, and nutrient analyses. Interpreting the mechanism responsible for differences will be accomplished through evaluating change in volatile profiles. Intervention strategies previously developed for fluorescent lights, including active packaging and antioxidant supplementation, will then be appraised. Finally, consumer testing will evaluate the efficacy of interventions on improving overall liking, and perceived food quality.