Document Type

Dissertation - Open Access

Award Date

2022

Degree Name

Doctor of Philosophy (PhD)

Department / School

Dairy and Food Science

First Advisor

Lloyd Metzger

Keywords

Emulsifying salts, Functional properties, Lactose-6-phosphate, Milk permeate, Phosphorylation, Processed cheese food

Abstract

Lactose is the primary carbohydrate in most mammals' milk, commonly known as milk sugar. Milk permeate is a by-product of whey protein manufacturing through membrane technologies. It is cost-effective, available, and an excellent source of lactose. Sugar phosphorylation is a technique used to alter sugar's characteristics. It has numerous applications for developing dairy and food products. Lactose-6-phosphate (LP) is an organic compound that switches the hydrogen on lactose by monophosphate that has the potential to function as emulsifying salts (ES). ES, such as disodium phosphate (DSP) and trisodium citrate, have a critical effect on the emulsification characteristics of casein by sequestering the calcium from the calcium-paracaseinate phosphate complex in natural cheese during processed cheese (PC) manufacturing. PC is a dairy product manufactured by combining dairy and non-dairy components and heating the mixture with agitation to create a homogenous product with a long shelf life. The first objective of this study was to develop a method to phosphorylate α- lactose (LaP1), and milk permeate powder (LaP2) at specific concentrations that include pH, temperature, and time. A mass spectrometry (MS) was used to define LP in both treatments. Two samples were applied as controls. Control 1 and control 2 were used α-lactose monohydrate and milk permeate powder (MPP), respectively. The amount of lactose was lower in LaP1 (15.58%) and LaP2 (12.20%) compared to control 1 (69.32%) and control 2 (24.64%). However, the level of LP was increased in LaP1 (60.74%) and LaP2 (8.65%), which were 0.89 and 5.53% for control 1 and control 2, respectively. We conclude that lactose and milk permeate can be phosphorylated, and MS can be used to detect lactose and LP. The objective of the second study was to remove the dark color of LaP1 and LaP2 solutions. During the phosphorylation process, the color of the solutions turns dark. Activated carbon has been utilized for decades to remove the dark color and improve the appearance of solutions. The usage of activated carbon has been expanded to include decolorization, gas separation and polluted air treatment, heavy metal recovery, and food processing with no hazard. This methodology is cheap method and environmentally friendly. The compositional characteristics of the solutions, such as pH, total solids (TS), and color parameters (L*- lightness, a*- redness, and b*- yellowness) were examined at different stages (seven stages) of washing the solutions. Both solutions' pH and TS decreased with increasing the number of washings with activated carbon. The L* of the initial solutions was lower than the final solutions. However, the a* and b* of the initial solutions were higher than the final solutions. The total color difference (ΔE) was calculated for both solutions. ΔE was decreased with increasing the number of washings with activated carbon in both solutions. The findings of this study indicate that activated carbon can be used to remove the dark color that results from the phosphorylation process. The objective of the third study was to produce processed cheese food (PCF) with LaP1 (52% TS) instead of DSP. PCF is a dairy product prepared by blending dairy ingredients with non-dairy ingredients and heating the blend with agitation to produce a homogeneous product with an extended shelf-life. The ingredients in the PCF formulations were Cheddar cheese, butter, water, milk permeate powder, and LaP1 (at a ratio of 2.0, 2.4, 2.8, 3.2, 4.0, 5.0, and 6.0%) were formulated to contain 17.0% protein, 25.0% fat, 44.0% moisture, and 2.0% salt. The LP concentrations in LaP1 solutions were ranged between 0.63 to 1.9%. The PCF made with 2.0% DSP was also produced as a control. The PCF was analyzed for moisture, pH, end apparent cooked viscosity, hardness, melted diameter, and melting temperature. The moisture of PCF ranged from 42.3 to 44.0%, with a pH of 5.6 to 5.8. The end apparent cooked viscosity increased from 818.0 to 2060.0 cP as the level of LaP1 solution raised from 2.0 to 6.0%, while it was 660.0 cP in control. The hardness of PCF made with LaP1 elevated from 61.9 to 110.1 g as the level of LaP1 increased; however, it was 85.6 g in control. The melted diameter decreased from 43 mm in control to 29 mm in 6% LaP1, while the melting temperature of PCF increased from 37.7°C in control to 59.0°C in 6% LaP1. We conclude that LaP1 can be utilized as a substitute for DSP in PCF manufacture. The objective of the final study was to produce PCF using LaP2 (70% TS). The amount of LP was 0.48%. The ingredients in the PCF formulations were Cheddar cheese, butter, water, MPP, and LaP2 (8.0%). Those ingredients were formulated to contain 17.0% protein, 25.0% fat, 43.0% moisture, and 2.0% salt. PCF with 2.5% DSP was also produced as a control. The experiment was repeated 5 times using five different batches of LaP2 solutions. The moisture of PCF ranged from 42.61 and 43.09%. The pH was 5.81 for PCF made with LaP2; however, it was 5.74 in control. The cooked viscosity of LaP2 was 2032.0 cP, while it was 1378.0 cP in control. The hardness of PCF made with LaP2 was 154.5 g and 91.6 g in control. The melted diameter decreased from 41.0 mm in control to 34.0 mm in LaP2, while the melting temperature of PCF increased from 43.2°C in control to 46.5°C in LaP2. We conclude that LaP2 can be utilized as a substitute for DSP in PCF manufacture.

Number of Pages

202

Publisher

South Dakota State University

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Rights Statement

In Copyright