Elizabeth Eckelkamp

Fourier transform infrared spectroscopy (FTIR) has become an increasingly valuable analytical tool in the dairy industry due to its rapid, non-destructive nature and ability to capture complex chemical information. This study evaluated the feasibility of using FTIR in combination with chemometric modeling to predict the freezing point (FP) of ice cream mix (ICM), an important quality attribute that influences product texture, freezing behavior, and manufacturing efficiency. Traditional methods for FP determination are often labor-intensive and can present challenges when analyzing high-solids dairy systems. In this study, FP values were obtained through a cryoscopic method. FTIR spectra were collected for all samples, and partial least squares (PLS) regression models were developed to relate spectral information to FP values. Model performance metrics indicated that FTIR spectra contained information associated with FP variation; however, overall predictive performance was limited. The relatively weak model accuracy was attributed to the complex nature of FP as a colligative property influenced by multiple compositional factors, including sugars, salts, proteins, and stabilizers, as well as the narrow compositional range and limited sample size of the dataset. Despite these limitations, the results demonstrated the potential of FTIR as a rapid screening tool for FP estimation and provided a foundation for future model development using larger and more compositionally diverse datasets and improved reference methodologies.

There has been little research on freezing-induced damage in high-moisture dairy products, specifically sour cream and yogurt. This work aimed to investigate, as a proof-of-concept, if antifreeze additives may prevent quality decrease in high-moisture dairy products due to freeze-induced damage. Whey protein isolate and soy protein isolate were complexed with locust bean gum and lambda carrageenan, in both unhydrolyzed and hydrolyzed forms, and their antifreeze activity was evaluated in a model system as well as in sour cream and yogurt. The biomolecules were also tested individually as controls to determine any synergistic effects. Protein and polysaccharide complexes were found to have ice recrystallization inhibition activity in the model systems by reducing the ice crystal size significantly (35–64%) compared to the negative control at both pH 4.5 and 7.0. However, the complexes failed to prevent freeze-induced damage in the dairy system and all treatments resulted in decreased firmness, cohesiveness, and consistency along with increased graininess, possibly due to the complex interacting with different food components that may have interfered with the antifreeze activity of the tested compounds.

Rationale: Freezing dairy foods can result in textural quality loss. There is a need for food‐grade antifreeze agents for long‐term storage.Aim: This study aimed to develop dairy protein–polysaccharide complexes, assess their ice recrystallisation inhibition effect and reduce freezing‐induced damage by incorporating them into a commercial cream cheese spread.Methods: Complex formation between whey protein isolate and locust bean gum (LBG) or lambda carrageenan (λCG), as well as complexes between their hydrolysates, was made and confirmed by particle size, zeta potential, surface hydrophobicity analyses and FTIR.Major Findings: The complexes made from the unhydrolyzed biopolymers showed ~66% ice crystal size relative to a negative control for both gum types. The cream cheese spread with complex addition at 4% dry‐weight basis and after repeated freeze‐thaw treatment cycles showed general trends of all complex treatments containing λCG having rheological and textural properties more similar to the fresh control spread compared to the protein alone and other treatments containing LBG. The storage modulus (G’) of the treatments with complexes formed between WPI and λCG and their hydrolysates are between 200–250 KPa, similar to that of untreated control. The adhesiveness of the treatments with complexes formed between WPI and λCG and their hydrolysates, as well as the λCG gums, are also more similar to the controls (50 vs 25 g.sec), compared to the other treatments (150–250 g.sec).Industrial Implications: When the study is further validated by applying the treatments to the proper processing steps and products evaluated under more relevant conditions, the impact of such novel antifreezing complex on dairy product quality will be better demonstrated.

Whey, the largest co‐product source of the dairy industry, contains highly valued components such as phospholipids. For this work, cheddar cheese whey's phospholipids were precipitated using thermocalcic aggregation. The impact of calcium acetate concentration, pH, and temperature as processing conditions was evaluated. The results showed that the highest recovery of phospholipids was achieved at pH 6.5, a calcium acetate concentration of 50 mM, and at a temperature of 60 °C. Calcium acetate concentration and pH were statistically significant factors (p < 0.05), but temperature was not. For all treatments, the majority (95%–98%) of the protein remained in the supernatant. Under the identified best conditions, up to 92% of the phospholipids of the milk fat globule membrane were precipitated in the pellet, while 96% of the proteins remained in the supernatant. The salt recovery, that is, in the precipitate, was 53%, but decreasing the amount of salt used would result in incomplete recovery of the phospholipids. Gel electrophoresis showed that the majority of the globule membrane proteins were precipitated into the pellet, while the supernatant only contained major whey proteins. This procedure demonstrates a simple and cost‐effective method to utilize cheese whey for phospholipids precipitation that can be further processed into a value‐added food or nutraceutical ingredient. This technique, after more fully optimized, would allow for easy implementation in small cheese production facilities.

Wearable precision dairy monitoring (PDM) technologies currently used to detect estrus may provide insight into disease detection. However, the incorporation of PDM into farm management and its perceived usefulness for dairy producers have not been explored. As the targeted end users of these products, information is needed on how producers use generated disease alerts as well as barriers to adoption and usefulness. The objective of this research was to assess the perceived usefulness producers attributed to alerts from a daily generated alert list designed to identify sick or injured cows or cows that experienced a major management change. Data from 1,171 cows on 4 commercial farms in Kentucky were collected from October 2015 to October 2016. Each cow was equipped with 2 PDM technologies: a leg tag (measuring activity in steps/d and lying time in h/d) and a neck collar (measuring eating time in h/d). Alerts were generated based on an individual cow's decrease of ≥30% in activity, lying, and eating time compared with each cow's 10-d moving mean. Producers sorted alerts into 3 overall categories: (1) the cow alert was perceived to be true and the cow was visually checked, (2) the cow alert was perceived to be true, but the cow was not visually checked, and (3) the cow alert behavior change was doubted by the producer and the cow was not visually checked. Further subdivisions were also provided to explain the choice for an overall category. Over the year, 24,012 cow alerts were generated (eating time, n = 9,543; lying time, n = 9,777; activity, n = 1,590; or a combination of behaviors, n = 3,102). Only 8% of the alerts were doubted by the producer. Although 55% of alerts were perceived to be true, producers visually assessed cows based on only 21% of the alerts with a large variation between farms (2 to 45% of the alerts visually assessed). Producers were more likely to completely ignore alerts over time. Producers were more likely to perceive cow alerts to be true and visually check cows when ≤20 alerts occurred per day, cows were fresh or in early lactation, alerts occurred during the work week, or when cow alerts were for eating time, activity, or a combination of multiple behaviors. Behavioral disease alerts must be improved and correspond to an actionable change for producers to use them. Incorporating herd management software, creating and managing alerts by lactation stage, and focusing on behaviors producers already find useful could improve future alert utilization.