Invited review: Maintaining and growing fluid milk consumption by children in school lunch programs in the United States

Gram-negative postpasteurization contamination patterns of single-serve fluid milk produced in 4 different processing facilities

An analysis of historic data on high temperature, short time (HTST) fluid milk quality showed higher total bacterial counts and lower sensory defect judging scores at d 14 postprocessing for milk packaged in single-serve containers as compared with milk packaged in half-gallon containers from the same processing facilities. As postpasteurization contamination with gram-negative bacteria is likely a major contributor to an increased spoilage risk associated with milk packaged in single-serve containers, we performed a comprehensive assessment of the microbial quality and shelf life of 265 commingled single-serve HTST fluid milk samples (including white [unflavored] skim, white [unflavored] 1%, chocolate skim, and chocolate 1%) collected over 2 visits to 4 commercial fluid milk processing facilities. Over 2 initial sampling visits, the frequency of gram-negative spoilage ranged from 14 to 79% of the product collected from the 4 facilities, with significant differences of gram-negative spoilage frequency between sampling visits, facilities (sampling visit 1, sampling visit 2, and both sampling visits combined), milk types (sampling visit 2), and filler lanes (sampling visit 2). We found no significant differences in the frequency of gram-negative spoilage between sampling time points (e.g., beginning, middle, and end of production run). Across facilities, single-serve containers of milk with gram-negative contamination showed significantly higher bacterial counts on d 7 and 14 and significantly lower sensory scores as compared with those without gram-negative contamination. Follow-up investigations, based on in-facility surveys that identified carton forming mandrels as filler components that frequently failed quality assurance ATP swab checks, found that bacterial genera, including Pseudomonas and Bacillus, isolated from single-serve milk samples were also frequently isolated from mandrels. Although interventions aimed at improving cleaning and sanitation of mandrels did not lead to significant reduction of gram-negative spoilage frequency in a comparison of 398 control and 400 intervention samples, our data still suggest that the unhygienic design of single-serve fillers is likely a root cause of gram-negative contamination of single-serve milk.

Parental perception of children's school lunch milk

School lunch programs are mandated by the US Code of Federal Regulations to serve pasteurized milk that is skim or 1% fat and fortified with vitamins A and D. In recent years, proposals have been made to alter nutritional requirements for school lunches and school lunch milk, including changes to the milk fat and flavor options available. The objective of this study was to evaluate parental understanding and perception of school lunch milk to better understand how changes to school lunch milk are perceived by parents. Four focus groups (n = 34) were conducted with parents of school-aged children (5-13 yr) who purchased milk as part of a lunch at school. Participants were asked about school lunch milk, including nutritional content, packaging, and flavoring. Focus groups included a build-your-own milk activity and discussion of children's milk products currently available on the market. Two subsequent online surveys were conducted with parents of school-aged children (survey 1, n = 216; survey 2, n = 133). Maximum difference scaling was used to evaluate what beverages parents would prefer their child to drink at school (survey 1) and which attributes of chocolate milk for children were most important to parents (survey 2). An adaptive choice-based conjoint activity (survey 1) included flavor, milk fat, heat treatment, label claims, and packaging type. Both surveys included questions to evaluate knowledge of milk nutrition and attitudes regarding milk and flavored milk. Agree/disagree questions were used in both surveys to assess parental opinions of school lunch milk. Survey 2 also included semantic differential (sliding scale) questions to assess parental opinions of chocolate milk and their acceptance of sugar alternatives in chocolate milk served in schools. Parents were familiar with the flavor options and packaging of school lunch milk, but expressed limited familiarity with school lunch milk fat content. Parents perceived milk to be healthy and a good source of vitamin D and calcium. From survey results, parents placed the highest importance on school lunch milk packaging, followed by milk fat percentage and flavoring over label claims and heat treatment. The ideal school lunch milk for parents was unflavored (white milk) or chocolate, 2% fat, and packaged in a cardboard gabletop carton. For school lunch chocolate milk, 3 distinct clusters of parents with differing opinions for children's chocolate milk were identified. Parents are largely unfamiliar with the specific attributes and nutritional profile of milk served in schools but believe that schools should offer milk to their children as part of breakfast and lunch. Parents in both surveys also displayed a preference for 2% fat milk over low-fat options, which provides actionable insight for both governmental bodies determining educational and nutritional policies for school meals and fluid milk producers seeking to optimize their products intended for schools.

Determinants of the attitudes of proinnovative dairy consumers and a model simulating consumer behavior regarding increasing calcium intake

OBJECTIVE

A study was carried out to identify characteristics of consumers of dairy products.

METHODS

Based on a questionnaire with 127 participants, aged 22 to 52, a simulation model was developed, taking into account factors influencing the development of health-seeking behavior.

RESULTS

A relationship was found between consumer proinnovative attitude, actual prohealth behavior, and characteristics of the consumer influencing the consumption of calcium. Prohealth behavior (knowledge and application of the principles of healthy eating) is mainly influenced by material situation, age, and gender of the consumer. It has been reported that only 25% of parents talk to their children about the principles of healthy eating. No relationship was found between prohealth and proinnovation behaviors and level of education, sports activity, or number of children in the family.

CONCLUSIONS

Among young people, as many as 39% do not follow the principles of healthy eating, and these are mainly women. Respondents' proinnovative attitudes and social status were conducive to increasing calcium intake and correlate with greater diversity in the consumption of dairy products. The Pearson correlation coefficient between body mass index and calcium intake was not significant (r = -0.03; P = 0.76).

Perspective: School Meal Programs Require Higher Vitamin D Fortification Levels in Milk Products and Plant-Based Alternatives-Evidence from the National Health and Nutrition Examination Surveys (NHANES 2001-2018)

Poor vitamin D status impairs bone growth and immune defense in school-aged children and adolescents, particularly in minorities. Vitamin D insufficiency/deficiency increases the risk of acute viral respiratory infection, underscoring the need for adequate vitamin D intakes during school sessions when viral exposure may be greatest. We studied available vitamin D-related survey data and published findings based on NHANES (2001-2018) to assess the dependency of vitamin D status {25-hydroxyvitamin D [25(OH)D]; in nmol/L} on vitamin D intake (μg/d) in elementary school-aged children (4-8 y), middle school children (9-13 y), and high school adolescents (14-18 y). We sought evidence supporting the need for school programs to facilitate vitamin D adequacy. Usual vitamin D intakes from food and beverages by children/adolescents (NHANES 2015-2018) examined at the 50th percentile intake by race/ethnicity (non-Hispanic White, non-Hispanic Black, Hispanic) showed all age groups consumed less than half of the Estimated Average Requirement (EAR) for vitamin D (10 μg/d), independent of race/ethnicity. NHANES (2001-2010) analyses show evidence of lower vitamin D status in school-aged children that is linked to lower intakes of fortified milk varying over race/ethnicity and age. Adolescents had lower vitamin D status and milk intake than younger children. A total of 22-44% of vitamin D intakes occurred away from home, with larger percentages of total intakes at breakfast and lunch, at times consistent with school meals. Ever-present inadequate vitamin D intakes with a large percentage consumed away from home together with well-established benefits to growth, bone, and immune defense from enriched vitamin D-fortified milk in school intervention trials provide strong justification to require enriched vitamin D-fortified foods in school meals. An easy to implement plan for improving vitamin D intakes is possible through the FDA's amendment allowing higher vitamin D fortification levels of dairy and plant-based milk alternatives that could increase vitamin D intakes beyond the EAR with just 2 daily servings.

Patterns Of Food Security And Dietary Intake During The First Half Of The Child Tax Credit Expansion

Temporary expansion of the Child Tax Credit (CTC) during the COVID-19 pandemic provided additional monthly income for US families, with no restrictions on use, from July through December 2021. This study examined food security and children's dietary intake after three months of expanded CTC payments. Parents completed online surveys before and after three months of CTC payments. Among parents participating in the expansion, food and beverage purchases were the most common use of expanded CTC funds (45.9 percent), particularly in households with very low food security (63.0 percent). From before to midway through the CTC expansion, very low food security decreased from 12.7 percent to 5.6 percent, and simultaneously, food security increased from 57.4 percent to 66.4 percent. The CTC expansion was also associated with decreases in children's consumption of added sugar, sugar-sweetened beverages, and sweetened fruit beverages. No changes were observed in children's intake of other dietary components. Our findings suggest that the expanded CTC payments may have helped lessen food insecurity and supported reductions in children's intake of added sugar in participating households.

Children's perceptions of fluid milk with varying levels of milkfat

Schools participating in federal meal programs are limited to serving skim or low-fat (≤1%) flavored and unflavored milk. Few studies have directly addressed child perceptions and preferences for milk containing different amounts of milkfat. The objective of this study was to determine whether children can differentiate between flavored and unflavored fluid milk containing varying levels of milkfat and whether preferences for certain levels of milkfat exist. Flavored and unflavored milks containing 4 different percentages of milkfat (≤0.5, 1, 2, and 3.25%) were high-temperature, short-time processed, filled into half-gallon light-shielded milk jugs, and stored at 4°C in the dark. Milks were evaluated by children (ages 8-13 yr) following 7 d at 4°C. Acceptance testing and tetrad difference testing were conducted on flavored and unflavored milks with and without visual cues to determine if differences were driven by visual or flavor or mouthfeel cues. Child acceptance testing (n = 138 unflavored; n = 123 flavored) was conducted to evaluate liking and perception of selected attributes. Tetrad testing (n = 127 unflavored; n = 129 flavored) was conducted to determine if children could differentiate between different fat levels even in the absence of a difference in acceptance. The experiment was replicated twice. When visual cues were present, children had higher overall liking for 1% and 2% milks than skim for unflavored milk and higher liking for chocolate milks containing at least 1% milk fat than for skim. Differences in liking were driven by appearance, viscosity, and flavor. In the absence of visual cues, no differences were observed in liking or flavor or mouthfeel attributes for unflavored milk but higher liking for at least 1% milk fat in chocolate milk compared with skim was consistent with the presence of visual cues. From tetrad testing, children could visually tell a difference between all unflavored pairs except 2% versus whole milk and could not detect consistent differences between milkfat pairs in the absence of visual cues. For chocolate milk, children could tell a difference between all milk fat pairs with visual cues and could tell a difference between skim versus 2% and skim versus whole milk without visual cues. These results demonstrate that in the absence of package-related flavors, school-age children like unflavored skim milk as well as milk with higher fat content in the absence of visual cues. In contrast, appearance as well as flavor and mouthfeel attributes play a role in children's liking as well as their ability to discriminate between chocolate milks containing different amounts of fat, with chocolate milk containing at least 1% fat preferred. The sensory quality of school lunch milk is vital to child preference, and processing efforts are needed to maximize school milk sensory quality.

Is Ultra-High Temperature Processed Milk Safe in Terms of Heterocyclic Aromatic Amines?

Herein, the presence of heterocyclic aromatic amines (HAAs) in 24 different commercial ultra-high temperature processed (UHT) milk types was investigated. The dry matter and pH values of the samples were also determined. The milk types showed significant differences (p < 0.01) regarding the dry matter, pH values, and individual HAAs and total HAAs. The milk sample dry matter and pH values were in the range of 8.56-13.92% and 6.66-6.91, respectively. The growing up milk samples had the highest dry matter and pH values. While no significant correlation between the total HAAs and dry matter was found, a negative correlation (p < 0.01) between the total HAAs and pH value was determined. Among the tested HAAs, five compounds, (IQx (up to 0.06 ng), IQ (up to 0.10 ng), MeIQx (up to 0.55 ng), MeIQ (up to 1.97 ng), and PhIP (up to 0.39 ng)) were quantified in the samples. The average total HAAs of the samples ranged from 0.13 to 0.67 ng; however, one milk sample (200 mL) contained between 10.10 and 53.35 ng total HAAs. Therefore, it was shown that protein fortification and lactose hydrolysis substantially increased the formation of HAAs in UHT milk.

Child preferences and perceptions of fluid milk in school meal programs

School meal programs in the United States feed approximately 30 million children each day and account for the majority of child milk intake. Dairy consumption during childhood and adolescence has lasting effects on lifelong health status, so it is important for schools to ensure adequate consumption in this life stage by offering an appealing product. This study identified the intrinsic and extrinsic attributes that influence children's perceptions, attitudes, and consumption of fluid milk at school, especially as they relate to fluid milk packaging. An online choice-based conjoint survey (n = 211) and four 1-h focus groups (n = 31) were conducted with child milk consumers ages 8 to 13 yr to evaluate extrinsic attributes. The survey evaluated milk package attributes including packaging type, front-of-package graphics, package color, and labeled milk fat content. Focus group topics included preferences, usability, health, taste of fluid milk, and milk consumption habits. To evaluate intrinsic properties related to packaging, 3 varieties of milk (unflavored fat-free, unflavored low-fat, and chocolate-flavored fat-free) were produced and packaged in polyethylene-coated paperboard cartons, polyethylene terephthalate (PET) bottles, and high-density polyethylene (HDPE) bottles (all 250 mL). After 10 to 13 d of storage at 4°C under dark conditions, milks were evaluated by descriptive analysis and child acceptance testing (ages 8-13 yr; n = 126, 122, and 126 for each variety, respectively). Extrinsically, package type was the most important attribute to children, but graphics, nutritional labeling, branding, package size, and overall familiarity also drove preferences. The ideal milk packaging build from the conjoint survey was an HDPE bottle with blue-colored packaging and a cow graphic, labeled as low-fat milk. Intrinsically, all varieties of milks packaged in paperboard cartons developed package-specific flavors, including refrigerator/stale and paperboard, after 10 d of storage. These off-flavors were not detected in HDPE- or PET-packaged milks. For unflavored milks, child consumers preferred the flavor of PET- or HDPE-packaged milks over cartons, regardless of milk fat content, but preferences were not distinct for chocolate-flavored milk. The results of this study demonstrate that children's liking and preference for milk are driven by both intrinsic and extrinsic factors and suggest that improvements are needed to increase acceptance of milk currently served in school meal programs.