Cheese feed to powder: Factors affecting the cheese feed and powder properties

Research output: Book/ReportPh.D. thesisResearch

  • Denise Felix Da Silva Tenório
Cheese powder is a multifunctional ingredient used in ready meals, sauces, soups, and dressings to provide a unique combination of taste, functionality, and convenience. Cheese powders are produced by spray drying a mixture of minced cheeses, water and other ingredients, such as emulsifying salts (ES), heated to form a homogeneous emulsion, termed cheese feed. Cheese feed and powder properties such as physical, chemical and functional properties can be affected by the use of different cheese raw materials, addition of ingredients, homogenization, spray drying, dry mixing, and storage conditions. Thus, this PhD thesis aims to investigate the various factors affecting the cheese feed and powder properties to produce functional cheese powders with superior quality. In addition, significant emphasis is placed on developing and understanding the properties of cheese powders without the addition of ES.T he homogeneity, stability, and flow behavior of cheese feeds are important for further processing and final product quality. In this research, cheese feeds produced with various formulations are explored. The consistency coefficient (K) and flow behavior index (n) are estimated using the Power Law model, which indicate that all cheese feeds behave as a non-Newtonian shear-thinning (pseudoplastic) fluid with flow behavior index n < 1. In feeds produced only with Camembert cheeses without the addition of ES, the main factors affecting cheese feed homogeneity are fat content followed by calcium and phosphorus content, which exert a negative influence on feed homogeneity. Feeds produced mainly with Cheddar cheese show different stability depending on the type of ingredients, including ES. Feeds are designed to replace ES for dairy ingredients, thereby, feeds containing 2% buttermilk powder plus 2% sodium caseinate (B2S2) do not reveal any phase separation, indicating good stability as a result of the synergic effect of buttermilk powder and sodium caseinate. Moreover, the oil droplet particle size does not affect the stability of those cheese feeds significantly. Also, very good stability was achieved when ingredients were added to feeds manufactured with Danbo cheeses with varying cheese age (16, 30 and 45 weeks). Hence, the addition of these ingredients leads to a decrease in the K in cheese feeds made from 16 and 30 weeks old Danbo cheeses but does not affect feeds produced with 45weeksold Danbo. In the cheese powder, ES absence causes the formation of more irregular and rough powder particles, which may be due to the presence of free fat on the particle surface. No differences in water or fat mobility in the dried powders are observed by 1H low field nuclear magnetic resonance. Agglomerated powder particles indicate enhanced swelling but unchanged total rehydration properties compared to non-agglomerated powder. The presence of lactose in the amorphous state creates powders with smaller particles, faster dissociation in water, better solubility, and rehydration ability. B2S2 powders present homogeneous particle size distributions, lower amounts of free fat, and better flowability due to improved fat emulsification. Powders containing 4% buttermilk powder (BMP) are marked by higher browning index, cohesiveness, spontaneous primary agglomeration and higher sensitivity to browning. No correlation is identified for flowability of cheese powders with their particle size. Cheese powder properties can thus be significantly improved by the addition of 2% buttermilk powder plus 2% sodium caseinate, whereas no improvements are observed using only buttermilk powder. In addition, B2S2 cheese powders show improved wettability by capillary forces. Powders containing only buttermilk powder as well as powders produced with 45 weeks old cheeses present faster dispersibility and weaker interactions with the water (total rehydration). In contrast, B2S2 presents a delayed dispersibility. Only two types of water population (water fractions) are identified for reconstituted powders produced with 16 weeks old cheese, lacking the most free water component implying in better total rehydration. These findings indicate that each stage of reconstitution of cheese powder is determined by a specific factor.In addition, the emulsification properties of various cheese powders are assessed. Emulsions produced using cheese powders containing ES have higher pH and zeta potential, a more Newtonian behavior and improved physical stability compared to cheese powder without ES. The physical stability of emulsions is significantly improved with an increase in protein content. Completely stable emulsions for up to 20 days are obtained with cheese powders at a concentration of 4.5% protein, making it possible to stabilize an emulsion with cheese powder either with or without ES. Lastly, cheese age (ripening time) significantly affects the stability of emulsions containing cheese powders at a concentration of 1.5 % in protein basis. Initially, the use of 16 weeks old cheese powder reveals a lower degree of instability with a gradual increase in phase separation reaching to 2.5 cm length of clarified phase over 10 days of storage. However, when older cheese powders are used, faster instability is observed reaching the maximum length of phase separation after 1 day of storage, but to a lower extent (1.5 or 1 cm length). Therefore, this thesis provides new knowledge regarding the main factors affecting cheese powders. More specifically, it provides data, methods, and quality control inputs for manufacturing tailor-made cheese powders with desired quality and functionality in food products.
Original languageEnglish
PublisherDepartment of Food Science, Faculty of Science, University of Copenhagen
Publication statusPublished - 2018

ID: 209116034