The effect of spray-drying parameters on the flavor of nonfat dry milk and milk protein concentrate 70%

Abstract

Unit operations during production influence the sensory properties of nonfat dry milk (NFDM) and milk protein concentrate (MPC). Off-flavors in dried dairy ingredients decrease consumer acceptance of ingredient applications. Previous work has shown that spray-drying parameters affect physical and sensory properties of whole milk powder and whey protein concentrate. The objective of this study was to determine the effect of inlet temperature and feed solids concentration on the flavor of NFDM and MPC 70% (MPC70). Condensed skim milk (50% solids) and condensed liquid MPC70 (32% solids) were produced using pilot-scale dairy processing equipment. The condensed products were then spray dried at either 160, 210, or 260°C inlet temperature and 30, 40, or 50% total solids for NFDM and 12, 22, or 32% for MPC70 in a randomized order. The entire experiment was replicated 3 times. Flavor of the NFDM and MPC70 was evaluated by sensory and instrumental volatile compound analyses. Surface free fat, particle size, and furosine were also analyzed. Both main effects (30, 40, and 50% solids and 160, 210, and 260°C inlet temperature) and interactions between solids concentration and inlet temperature were investigated. Interactions were not significant. In general, results were consistent for NFDM and MPC70. Increasing inlet temperature and feed solids concentration increased sweet aromatic flavor and decreased cardboard flavor and associated lipid oxidation products. Increases in furosine with increased inlet temperature and solids concentration indicated increased Maillard reactions during drying. Particle size increased and surface free fat decreased with increasing inlet temperature and solids concentration. These results demonstrate that increasing inlet temperatures and solids concentration during spray drying decrease off-flavor intensities in NFDM and MPC70 even though the heat treatment is greater compared with low temperature and low solids.

The anti-inflammatory effect of milk and dairy products on periodontal cells: an in vitro approach

“…The underlying molecular mechanism responsible for the anti-inflammatory effect of milk and its respective products remains open. Considering that casein and whey hydrolysates display an anti-inflammatory effect on colon and respiratory epithelial cells [5,6], together with our findings based on fermented milk products and even powdered milk (the latter being heated up to 160°C) [11], it is likely that a milk component which resists heating and fermentation is responsible for the anti-inflammatory activity in the various cell types. Soluble TNFα receptors IL1Ra neutralizing the bioactivity of the respective cytokines [28,29] are present in milk but are presumably not that heat stable to exert the antiinflammatory activity of powdered milk.…”

“…Pasteurization usually occurs at approximately 72°C for 15 s [8] and for the preparation of yoghurt, milk is heated to 80°C to 95°C for 10 to 30 min [9,10]. Powdered milk is heated to 160°C or higher [11]. On the other hand, for the production of cheese, casein is cleaved by rennet extract, or by enzymes derived from plants, fungi, and microbial sources [12].…”

Antiinflammatory effect of milk and dairy products on periodontal cells- an in vitro approach

“…The underlying molecular mechanism responsible for the anti-inflammatory effect of milk and its respective products remains open. Considering that casein and whey hydrolysates display an anti-inflammatory effect on colon and respiratory epithelial cells [5,6], together with our findings based on fermented milk products and even powdered milk (the latter being heated up to 160°C) [11], it is likely that a milk component which resists heating and fermentation is responsible for the anti-inflammatory activity in the various cell types. Soluble TNFα receptors IL1Ra neutralizing the bioactivity of the respective cytokines [28,29] are present in milk but are presumably not that heat stable to exert the antiinflammatory activity of powdered milk.…”

Effect of bovine feeding system (pasture or concentrate) on the oxidative and sensory shelf life of whole milk powder

“…This technique was employed to track the development of taste and odor attributes in WMP as LO progressed at 2 storage temperatures (21°C and 37°C) in opened lidded cans. Panelists (n = 9) were trained to rate the WMP samples based on selected relevant sensory attributes (Drake et al, 2003;Lloyd et al, 2009a,b;Park et al, 2016), which were defined and agreed upon by all panelists before final scoring. Analyses of TFA, FFA content, color, composition, sensory attributes, and volatile profile of the WMP were undertaken at 3 time points over a predefined period of 6 mo.…”