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Liposomes were developed with bioactive constituents (omega-3, omega-6, tocopherol) incorporated in acid food. They were made of soy phosphatidylcholine (SPC) allowing the encapsulation of antioxidant vitamin C (VC) and tocopherol. Stearic acid (SA) or calcium stearate (CaS) was added as a bilayer stabilizer. The structural and oxidative stability of the liposomes were studied considering the heat effect of pasteurization. Size was analyzed by light scattering; shape and structure were studied by optical and transmission electron microscopy, respectively. Membrane packing was studied with merocyanine 540. Surface charge and oxidative stability were analyzed by zeta potential and ORAC method, respectively. The liposomes showed significant stability in all of the parameters mentioned above and an important protective effect over thermolabile VC. To confirm their applicability in food, the rheological behavior and a sensory evaluation of liposomes with vitamin C and bioactive constituents were studied. The sensory evaluation of liposomes in orange juice was performed by the overall acceptability and triangular tests with 40 and 78 potential consumers, respectively. The incorporation of all liposomal formulation did not change the acceptability of orange juice. Noteworthy, SPC and SPC:SA systems had rheological behavior similar to a Newtonian fluid whereas that SPC:CaS presented a pseudoplastic one, both considered excellent for larger scale production. From all the obtained results, we can conclude that these liposomal formulations are suitable for food industry applications, incorporating bioactive constituents and generating functional orange juice that conserves its bioactivity after pasteurization.

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The main goal of this work was to develop an additive to fortify a widely consumed product with vitamins. Additives were made of soy phosphatidylcholine (SPC)‐based liposomes to encapsulate vitamin E (VE) and vitamin C (VC), and incorporated in chocolate milk to generate a functional food and posterior pasteurization. SPC contains essential fatty acids like omega‐3 and omega‐6 fatty acids. Stearic acid (SA) or calcium stearate (CaS) was incorporated as a liposome bilayer stabilizer. Characterization of liposomes involved size and surface charge, studied by light scattering and zeta potential, respectively. Liposome shape was analyzed by optical microscopy. Membrane packing was studied with merocyanine 540 and oxidative stability by the TBA and ORAC methods. The studies were made before and after pasteurization to study thermal stability. All formulations showed significant stability of the parameters analyzed, even after pasteurization, and a protective effect over VC, which is thermolabile. The release of vitamins was studied by dialysis. All additives were able to retain a high percentage of VE and VC. For food application, a sensory evaluation was performed in chocolate milk with liposomes. SPC:SA liposomes can be selected as food additives due to their acceptability and stability. Practical applications: Additives with a natural lipid SPC and vitamins E and C were developed to be incorporated in chocolate milk. They presented: (1) A significant stability of all analyzed parameters before and after pasteurization:   – biophysical stability: size, structure, shape, molecular membrane packing and surface charge.   – the oxidative stability: all had low peroxidation tendency.   – thermal stability: all had a protective effect over thermolabile vitamin C after pasteurization.   – temporal stability: all presented a high encapsulation of vitamins after 72 hours of dialysis. (2) Additives showed a Newtonian and pseudoplastic rheological behavior, both considered excellent for larger scale production. (3) Sensory evaluation of additives in commercial chocolate milk was performed by the overall acceptability with hedonic scale employing 40 potential consumers. SPC:SA formulation with vitamins was the most applicable. For all the above mentioned, the formulations, specially SPC:SA with vitamins E and C, are excellent candidates as additives to incorporated in chocolate milk. From liposomes to functional chocolate milk: Image: Liposomes: SPC, soy phosphatidylcholine; SA, stearic acid; CaS, calcium stearate. First graph: Vitamin C protection, pH > 5. Second graph: Sensory evaluation in chocolate milk, SPC:SA the best suited.

The aim of this chapter is to describe the use of bioactive compounds with beneficial effects on human health beyond their basic nutritional value. Bioactive compounds like vitamin E, vitamin C, and fatty acids (omega-3 and omega-6) have an important nutritional contribution and are related to the prevention of certain diseases with global impact such as cancer. However, the addition of vitamins in a food product is not easy: E is destroyed by UV-light, and C is dramatically reduced during heat processes. The use of liposomes as matrices to hold bioactive compounds appears to be a promising solution. Liposomes were made of natural soybean lecithin, which has a great nutritional importance, and more so combined with stearic acid or calcium stearate (CaS). Thus, this stabilize liposomes and contribute to the stability of bioactive compounds and to preserve their activity. The stability of bioactive compounds/liposomes incorporated into aqueous food must be demonstrated in properties such as oxidative tendency, morphology, size, and membrane packaging after heat treatment processes. But to make a product applicable at the commercial level, its texture and mouthfeel arising from the ingestion of drinkable foods are all-important to consumer's choice and sensory acceptability must not undergo any modification.

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Functional foods are those with health benefits but cannot incorporate and protect from oxidation or deterioration, maintaining the bioactive compounds (BC) activity. The liposomes have several advantages for BC encapsulation: ease of obtention, characterization, scaling-up, lipid protection for hydrophilic and lipophilic BC, and best, they are made with natural lipids of alimentary grade. In our studies, liposomes were made of soy phosphatidylcholine (SPC) with Stearic Acid or Calcium Stearate as membrane stabilizer. They encapsulated BC as vitamin E, vitamin C and folic acid (B9). The liposome’s design strategy is that SPC lipid’s components are BC like choline and essential fatty acids. These liposomes preserved and maintain the activity of the thermolabile vitamins C and B9. Like milk and fruit juice, in various food types can incorporate liposomes protecting BC. A series of laboratory studies will be performed to select the most stable liposomal formulations, like characterization, encapsulation efficiency, physicochemical, microbiological, thermal and sensory stability. Liposomes- BC design and development are discussed in the chapter. The food heat treatment and the conditions/storage time are also crucial and must be considered in these studies. Finally, incorporating the BC into a food production line is feasible with an excellent economic prospect until supermarket shelves are reached, like our food product proposal.

In the present study, liposomes with bioactive compounds (BC), vitamin E (VE) and vitamin C (VC), were characterised after pasteurisation and storage in chocolate milk. Liposomes were obtained using soy phosphatidylcholine (SPC), SPC with stearic acid (SA) or calcium stearate (CaS). Oxidative stability, size, shape and membrane packing were studied after pasteurisation and storage for 28 days at 4 °C. Oxidative stability was also studied after pasteurisation in extreme conditions: 6 months, 25 °C and light. The oxidative level determined in liposomes is much under the permitted limits, generating good quality food. SPC maintained stability in size, shape and membrane packing for 28 days at 4 °C. SPC:SA and SPC: CaS evidenced a decrease in liposomal aggregation and a higher membrane packing for 28 days at 4 °C, which favoured stability. These results were optimum because commercial functional milk must have a shelf life of 7 days at 4 °C. Pasteurised liposomes were incorporated in chocolate milk to study the sensory (after storage for 7 days at 4 °C) and microbiological stability. None of the liposomes contributed to the microbial load. SPC:SA presented high sensorial stability in the milk, being a potentially suitable medium to incorporate BC generating functional food.