Master of Science / Department of Grain Science and Industry / Charles R. Stark / A study was carried out to determine the effect of replacing fish meal with either soybean meal or poultry by-product meal on broiler performance and total feed cost per kg of gain. A second study evaluated the effect of storage time and trace minerals on the stability of vitamins stored at high temperature and relative humidity and their subsequent effects on broiler performance, bone strength and ash. A third study consisting of two experiments was conducted to determine the effects of particle size, diet, method of analysis (laboratory, ground and unground) and feed form (mash and pellet) on the crude protein predictability of the near infrared reflectance spectroscopy while using standard calibrations installed with the instrument. In study 1, three dietary treatments, 1) SBM-FM diet, 2) SBM diet and 3) SBM-PBM diet, were allocated to 36 pens using a completely randomized design with 12 replicates per treatment. Replacing FM with SBM and PBM in broiler diets improved growth performance and reduced total feed cost per kg of gain. In study 2, seven experimental treatments, 1) 0 d VP, 2) 30 d VTMP, 3) 30 d VP, 4) 60 d VTMP, 5) 60 d VP, 6) 90 d VTMP and 7) 90 d VP, were stored for 0, 30, 60 and 90 days, respectively in an environmentally controlled chamber at 29.4°C and 75%. Samples of treatments were analyzed, and loss of vitamin activity was calculated after storage. Treatments were added to broiler diets to determine the effect of loss of vitamin activity on broiler performance. Dietary treatments were set up as randomized complete block design in four batteries. Storing vitamins with trace minerals for 90 days increased loss of vitamin activity as compared to when stored as vitamin premix. Loss of vitamin activity did not significantly affect overall broiler performance, bone strength and ash. In study 3, Exp. 1 was a 3 × 3 × 4 factorial with corn particles size (400, 600 and 800 μm), method of analysis (laboratory, unground and ground) and diet (SD, SFD, SFB and SB). Diets were formulated to contain 20% crude protein. Subsamples were ground through a 0.5 mm sieve. Crude protein contents of ground and unground samples were analyzed using the Foss DS2500 NIRS (Model Foss DS2500 Monochromator, Foss NIRSystems, Laurel, MD) and compared to laboratory results from wet chemistry analysis. Interaction (P≤0.05) was observed between diet and method and particle size and method, but similar (P≥0.05) crude protein was observed for particle size. Diets and particle sizes were significantly different (P≤0.05) as unground samples but no differences (P≥0.05) were observed when ground and analyzed using the NIRS or wet chemistry. Exp. 2 was a 3 ×2 factorial with method of analysis (laboratory, unground and ground) and feed form (mash and pellet). Diets were formulated to contain 20% crude protein and manufactured with 600 μm corn particle size. Portions of diets were pelleted using a pellet mill and cooled. Ground and unground mash and pellets were analyzed as in Exp. 1. Interaction was found (P≤0.05) between feed form and method of analysis. Feed form and method of analysis significantly (P≤0.05) affected crude protein prediction from the NIRS. Crude protein content of ground mash and pellets were similar (P≥0.05) to that of laboratory results. Generally, analyzing finished feed samples in the unground form with the NIRS while using standard calibrations yielded less accurate predictions for crude protein, but samples in the ground form yielded similar (P≥0.05) results when analyzed with either the NIRS or wet chemistry.

Master of Science / Grain Science and Industry / Greg Aldrich / Processing pet food can be beneficial, but can also have adverse effects on shelf-life and nutrient survival. Most affected are supplemental vitamins and essential fatty acids (EFA). Pet food complicates this relative to human foods by combining all elements into the product before processing and requiring an extensive shelf-life (up to 2 years). The objective of this research was to determine the effects of processing, diet, and storage conditions on vitamin (vitamin A, vitamin D₃, vitamin E, folic acid and thiamine) and omega-3 fatty acid (with an emphasis on eicosapentaenoic acid; EPA 20:5n3, and docosahexaenoic acid; DHA; 22:6n3) retention. The research was conducted in two separate experiments. Each experimental diet was produced on a single-screw extruder and triple-pass dryer. Target nutrients were evaluated in premixes in tandem to extruded diets. The vitamin study was conducted as a 3 X 2 X 2 factorial arrangement of treatments with 3 levels of dietary crude protein (CP), 2 screw speeds in the extruder, and 2 levels of time X temperature combinations in the dryer. Vitamins were added at 10 times normal levels to aid in analysis. The EFA study was conducted as a 3 X 3 factorial arrangement of treatments with 3 levels of dietary protein and 3 different omega-3 sources: fish oil, fish meal, or purpose-grown algae rich in DHA. In the vitamin premix study, the quantity of vitamins declined by approximately 50% over 6 months storage in ambient conditions (AMB; 20C, 50%RH), and all except folic acid were lost to some degree in stressed shelf life testing (SSLT; 50C, 70% RH) over 6 weeks. In all cases, the concentration of vitamins in food exiting the extruder and dryer were lower than target levels. As CP increased, the retention was higher (P ≤ 0.05) for vitamins A, E, and folic acid off the extruder (e.g. 225,352 vs. 219,184 and 206,249 IU/kg of vitamin A for high vs. medium and low CP, respectively), and vitamin D₃, E, and folic acid off the dryer (e.g. 9,047 vs. 7,473 and 6,945 IU/kg of vitamin D₃ for high vs. medium and low CP, respectively). During storage of finished pet food in AMB, vitamins A and D₃ were lost (P < 0.05) to the greatest degree (49 and 22%, respectively). The total retention following both processing and AMB storage was 27, 68, 78% for vitamins A, D₃, and E, respectively, while folic acid and thiamine were relatively stable. In SSLT storage, all vitamins except vitamin E were depleted more than 60% (P < 0.05) by 24 weeks, whereas total retention following both processing and SSLT storage was 3, 59, 43, 33, and 7% for vitamins A, D₃, and E, folic acid, and thiamine, respectively. This would suggest that beyond processing losses, the vitamins are relatively stable in premixes and foods if stored in AMB conditions. In the study to evaluate fatty acid stability within a vitamin premix, EPA, DHA, and total omega-3 fatty acids were relatively stable during storage over 6 weeks with losses no greater than 12% in stressed shelf life testing (SSLT; 40C, 70% RH). While in ambient conditions (23C, 50% RH) over 3 months, there was a total loss of EPA, DHA and total fatty acids by 17, 9, and 11%, respectively. Exiting the extruder and dryer, EPA and DHA were not affected by CP level or Omega-3 source. As SSLT storage of finished pet food increased through 24 weeks, EPA, DHA, and total fatty acids declined slightly (P < 0.05; 125, 82 mg/kg for EPA and 77, 60 mg/kg for DHA, and 418, 476 mg/kg for total fatty acids at 0 vs. 24 wk. As time in ambient storage reached 24 months, EPA, DHA, and total fatty acids declined slightly (P < 0.05; 125 vs. 78 mg/kg for EPA and 77 vs. 50 mg/kg for DHA, and 387 vs. 373 for total fatty acids at 0 vs. 24 mo.) Algal-DHA appears to be a stable source of DHA when compared to fish oil and fishmeal. During processing retention of fat soluble vitamins was less than water soluble vitamins, and the omega-3 fatty acids were relatively unaffected. Whereas, vitamins appeared to be more sensitive to temperature during storage and the omega 3 fatty acids more affected by time.

Homogeneity of powder blends is an important metric for industrial applications in fortified dairy foods including commercial pediatric nutrition products. Product development practices evaluating physical properties and nutrient stability performance are reliant on blending parameters that deliver a uniform powder at both the pilot and commercial scale. Quantities of individual micronutrients in finished products are particularly critical for formulated infant foods. The two preliminary phases of this study focused on developing a simple, efficient method, specifically for a pilot scale ribbon blender, in which maximum homogeneity in fortified dairy-based powder blends could be reached. In phase one, a red iron oxide pigment powder was mixed throughout a white dairy powder and color homogeneity was measured by comparing L*a*b* color values from powder samples extracted from different areas of the ribbon blender. For phase two, sixteen similar fortified dairy blends were produced with varying ribbon blade shaft rpm, fill level, and blending durations according to a response surface method (RSM). The level of homogeneity of ferrous sulfate in the dairy blend was measured in these fortified mixtures to determine optimal blender parameters. After operating parameters were determined for uniform blending, phase three was enacted using these parameters. A comparison study of nutrient stability in fortified model non-agglomerated powder infant formula (PIF) and agglomerated whey protein concentrate (WPC) powder blends was executed to evaluate the degradative effect of microencapsulated ferrous sulfate (MFS) vs. unencapsulated ferrous sulfate (UFS) in these fortified dairy blends. The nutrient degradation rates of vitamins A, E and C in both PIF and WPC base powder, fortified with either MFS or UFS, were determined and compared during an accelerated eight-week stability study. Using p = 0.05, no statistically significant differences in vitamin degradation rates were observed when comparing independent spray-dried dairy-based blends containing unencapsulated or microencapsulated ferrous sulfate (using an encapsulating composition of 60% stearic acid) during eight weeks of accelerated shelf-life storage conditions (37 °C with a 75% relative humidity, RH). Of note, the degradation rates of vitamins A and E in blends containing PIF and UFS were more rapid than the control and suggestively significantly different (p = 0.07).

Fortification of instant Asian noodles with folic acid has the potential to enhance dietary folate intakes. Recent studies show folate deficiency is prevalent in many countries. Furthermore, this vitamin is unstable upon exposure to light, air, heat and extreme conditions of acidity and alkalinity. Internationally, folate in foods has traditionally been analysed by a microbiological assay, however, due to the extensive time required for sample preparation and analysis, alternative procedures for analysis require consideration. The aims of the current study have been to investigate the stability of added folic acid in fortified instant fried noodles by analytical methods of capillary electrophoresis and reversed-phase HPLC. Additionally, procedures for the microencapsulation of folic acid by spray drying have been evaluated along with their significance in increasing the stability of the vitamin during processing and boiling of instant noodles. Optimisation of capillary electrophoretic conditions showed that the maximum response of folic acid relative to an internal standard was achieved using various concentrations of phosphate and borate. Analytical parameters including the effects of pH, voltage and temperature were studied along with enzymatic treatments for liberation of folic acid from the noodle matrix based. Higher recoveries were obtained using the enzymes however these exceeded 100% due to sample matrix interference. Standard addition or internal calibration were both effective in correcting for matrix interferences. Comparative investigations with reversed-phase HPLC confirmed the results obtained with the capillary electrophoresis. Using either a phosphate based buffer in conjunction with an ion-pairing agent at alkaline pH or an acidic mobile phase, the results attained were in good agreement as folic acid exhibited excellent stability under typical processing conditions. Various food approved hydrocolloids were evaluated for encapsulation of folic acid by spray drying. Incorporation of the microcapsules into formulations of instant fried noodles showed that after boiling the folic acid was chemically degraded to some extent and leaching also occurred. The microcapsules exhibited similar properties regardless of the binding agent used, with losses still occurring during the boiling stage. In order to enhance the structural integrity of the spray dried microcapsules, CaCl2 was used as a cross-linking agent for capsules prepared using alginate or pectin binding agents. Considerable increases in retention of core material were observed as the network exhibited a reduction in swelling and hydration, and subsequently a decrease in the release of folic acid. In summary, capillary electrophoresis and reversed-phase HPLC provided excellent separation and good quantitatation of added folic acid in instant Asian noodles. Excellent resolution was obtained between the sample matrix interference of instant noodles and the analysed vitamin. Folic acid displayed high stability throughout the processing of instant noodles whereas there was consistent evidence that unencapsulated folic acid was degraded during boiling. Microencapsulation of folic acid with combinations of alginate and pectin as the binding agents, proved to be effective in maintaining folic acid stability when calcium treatment was performed after spray drying. These findings provide an effective way to retain folic acid used in fortifying Asian instant noodles.

The majority of water soluble vitamin and organic acid food additives are distributed in their crystalline forms. However, when they are combined with water and other food ingredients and then exposed to a variety of unit operations, there is potential to solidify these initially crystalline ingredients in the amorphous state. Amorphous solids are generally less chemically and physically stable than their crystalline counterparts. To ensure nutrient delivery to the consumer and fulfill labeling laws, deterioration of nutrients due to unintentional amorphization is undesirable. Additionally, the potential for recrystallization of an amorphous ingredient may alter texture and redistribute water. Hence, solid state form is a critical factor dictating the stability of food formulations. Building on earlier work from my M.S. degree that demonstrated thiamine chloride hydrochloride could solidify in the amorphous state in the presence of a variety of polymers (Arioglu-Tuncil et al., 2017), a major goal of this study was to develop a comprehensive understanding of the physical and chemical stability of amorphous forms of two thiamine salts, thiamine chloride hydrochloride (TClHCl) and thiamine mononitrate (TMN), in comparison to their crystalline counterparts and each other. The objectives for this part of the work were to investigate amorphization/recrystallization tendencies of TMN and TClHCl in solid dispersions, as well as chemical stability of thiamine in the solid dispersions to understand the impact of vitamin form, physical state (amorphous vs. crystalline), polymer type and features (Tg, hygroscopicity, and ability for intermolecular interactions), storage conditions, proportion of vitamin to polymer,and pre-lyophilized solution pHs on thiamine degradation and the physical stability of dispersions. Thiamine degraded more when in the amorphous form compared to in the crystalline state. Additionally, polymer type and vitamin proportion influenced thiamine degradation, where thiamine degraded more when it was present in lower concentrations (in dispersions that had higher Tgs), and it was chemically more stable when a polymer with greater intermolecular interactions with the vitamin was used. As storage RH increased, variably hygroscopicities of the polymers resulted in different thiamine degradation rates. The pre-lyophilization pHs of the solutions had a significant impact on thiamine stability in the solid dispersions. Similar to thiamine salts, citric acid is a commonly used food ingredient with a high crystallization tendency. Following similar experimental designs for documenting the recrystallization tendencies of citric acid in amorphous solid dispersions to those used in the thiamine studies, hydrogen bonding and/or ionic interactions between polymer and citric acid were found to be the main stabilizing factor for delaying recrystallization, more than polymer Tg and hygroscopicity. The findings of this dissertation provide a powerful prediction approach to physically and chemically stabilize the small compounds in the complex food matrices for the production of high quality food products and ensuring nutrient delivery to target populations.<br>