USING PSYCHOPHYSICAL, PHYSICOHEDONIC, AND CONSUMER CHOICE RESPONSES TO SWEETENER TECHNOLOGY TO SUPPORT MILK INTAKE IN ADOLESCENT WOMEN
Open Access
- Author:
- Reyes, Maridel Michelle
- Graduate Program:
- Food Science
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- August 08, 2017
- Committee Members:
- John E Hayes, Dissertation Advisor/Co-Advisor
John E Hayes, Committee Chair/Co-Chair
Gregory Ray Ziegler, Committee Member
Federico Miguel Harte, Committee Member
Kathleen Loralee Keller, Outside Member - Keywords:
- sweeteners
adolescent females
fluid milk intake
sensory science - Abstract:
- The sustained drop in milk consumption over time raises strong public health concerns regarding nutrient intake. This decline may be especially critical for adolescent girls, given the long-term implications of reduced calcium and vitamin D intake. Roughly 35-40% of children’s daily nutritional needs are met at school, thereby suggesting that a healthy school food environment is crucial to encourage healthy eating habits (Larson, Story et al. 2006). Recent changes to the National School Lunch Program (NSLP) nutritional standards limit flavoring to only skim milk and calories to 150 per serving (7 CFR 210.21). While the nutritional standards do not specifically restrict added sugars, sugar content cannot exceed 20 g/serving without surpassing the calorie limit. While evidence suggests recent reformulation of flavored milks has not resulted in a further drop in milk intake, these reformulations have also failed to increase fluid milk intake (Yon and Johnson 2015). To remedy this, we optimized flavored milks using novel blends of nutritive and nonnutritive sweeteners (NNS) to increase sweetness while minimizing adding sugars and thus calories. Extant data suggest children prefer sweeter solutions than do adults, with optimum sweetness around 19.2% ± 0.7% (w/v) sucrose (e.g., (Pepino and Mennella 2005), and focus groups with children in grades 5-7 (n = 72) found ‘taste’ was the main determinant for whether or not they would consume any beverage (Henry 2015). While some prior work has explored consumption and waste related to NSLP reformulated milk (Yon and Johnson 2013, Yon and Johnson 2015), there is currently a knowledge gap in the literature regarding hedonic testing of the reformulated flavored milks. We aim to address this gap here. We recently tested a wide range of approved sweeteners to quantify potential synergy using the response surface methodology from pharmacology (Berenbaum 1985, Suhnel 1992), and successfully identified novel combinations that exhibit true synergy. Understanding the v perceived intensity of blends can help product developers reduce caloric content of foods and beverages, especially when using NNS. Finding sweetener pairs that elicit the same level of sweetness can help reduce ingredient usage, thereby reducing total calories and undesirable side tastes associated with NNS such as bitter and metallic sensations (Allen, McGeary et al. 2013, Antenucci and Hayes 2015). Because of increasing consumer desire for products that deliver great taste with fewer calories, the commercial demand for improved zero- and reduced-calorie sweetener technologies will continue. NNS generally differ in taste from bulk nutritive sweeteners (e.g. sucrose) in the following ways: lower maximal intensity, undesirable side tastes, slower rates of onset, and persistence of sweetness (i.e., linger) (DuBois 2011). We investigated these qualities in sucrose and in NNS using a novel method called temporal check-all-that-apply (TCATA) to identify strategies for overcoming these sensory profile issues. Using TCATA, we were able to characterize the temporal taste and flavor profiles of commercially relevant NNS. Use of NNS potentially raises the issue of negative consumer beliefs and attitudes that likely influence intake, independent of scientific data on their safety. Accordingly, we investigated such beliefs using conjoint analysis in girls aged 12-19. Girls (n>400) were recruited nationally for an online study; they rated preference of various attributes, including milk flavor, sweetener type, added sugar content, caloric content, and messaging, prior to answering 21 choice-based conjoint (CBC) tasks. For each CBC task, girls evaluated 5 full profile choice sets and were told to choose which set they preferred. They then completed questionnaires on eating behavior, NNS attitudes, and demographics to provide additional insights into underlying motivations for their choices. From this study, we have gained insight into the ingredients, nutrient information, and messaging that is salient teenage girls, which can be used to formulate flavored milks that will most appeal to this nutritionally vulnerable population. vi Accordingly, we propose to leverage the insight gained from our previous synergy, TCATA, and conjoint studies to formulate flavored milks that a) have high acceptability, b) low energy density, and c) meet NSLP guidelines. The overall objective of our project is to a develop lower calorie chocolate milk for the NSLP that is highly acceptable to adolescent girls. Flavored milks were formulated using a three-component mixture design with varying levels of sucrose, stevia, and cocoa. Participants (n = 112) evaluated these milks for overall liking and attribute intensity; the most liked sample was then used for the paired preference study conducted in Bald Eagle Area Middle and High School. Participants (n = 161) were given 2 oz aliquots of milk and asked which sample she preferred. Results from our studies found that increasing stevia in reduced sucrose chocolate milk can maintain consumer acceptability. However, subsequent validation with paired preference did not confirm that the optimized product was equally liked as the current NSLP milk. This suggests that the product optimization study did not adequately investigate relevant ingredients and/or attributes that contribute to overall chocolate milk liking. The mixture design approach is a useful technique for product optimization, but researchers should be mindful of covering the entire relevant product space.