Semester of Graduation

Summer 2018

Degree

Master of Science (MS)

Department

Nutrition and Food Sciences

Document Type

Thesis

Abstract

Lactose intolerances in toddlers have become a major concern. Almond milk (AM) has nutritional benefits and a texture like dairy milk without the content of lactose. Because of longer stability and storage, milk is often stored in powdered form. An almond milk fortified with flaxseed oil in powdered form may be an alternative. Flaxseed oil (FO) contains high amounts of alpha-linolenic acid (ALA) which is a precursor to DHA and EPA. The objectives of this study were: the development of an AM spray-dried powder with microencapsulated FO (AMFOP), the determination of the mass and energy balance of that AMFOP production, and the evaluation of the physicochemical properties of the AMFOP for stability and quality.

AMs were homogenized with 2% or 4% FO and 8% maltodextrin for 1-minute. The maltodextrin was added as a microencapsulating agent. The AMs with FO and maltodextrin (AMFOs) were dried in a pilot-scale spray dryer at 150oC and mass and energy balances were calculated. The powders were denoted as 2AMFOP, 4AMFOP, and 0AMFOP (control). Two shelf-life studies were performed at 23oC and 40oC for 8-weeks. The powders were analyzed for physicochemical and rheological properties. Thiobarbituric-acid reactive substances (TBARS), color measurements, scanning electron microscopy (SEM), and light microscopy were performed. Triplicate experiments were conducted and statistically analyzed (P< 0.05).

The energy used (kJ/kg) to spray-dry the AMFOs was 11326.51+265.56, 11523.38+412.97, and 11669+412.97 for the 0AMFO, 2AMFO, 4AMFO, respectively. The measured production rate of AMFOPs was lower than their estimated production rates. TBARS (mg malondialdehyde equivalents/kg) for 4AMFOP (8.39+0.36) were significantly greater than 2AMFOP (6.16+0.51)and 0AMFOP (2.64+0.09) after 8-weeks at 23oC. 4AMFOP had higher color b* than 2AMFOP and 0AMFOP resulting in a yellower powder at 23oC. The quality of the 2AMFOP and 4AMFOP at 40oC after 6-weeks was deteriorated, resulting in water insolubility. SEM showed spherical morphology and microencapsulation of FO in 2AMFOP and 4AMFOP. This study demonstrated that 2AMFOP and 4AMFOP have sufficient stability for 8 weeks of storage at 23oC, however, 2AMFOP may be a better choice since its lower concentration of FO results in less oxidation.

Date

7-9-2018

Committee Chair

King, Joan.

DOI

10.31390/gradschool_theses.4769

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