Pasteurization of High Quality Organic Fruit and Vegetable Juices using Nonthermal Technologies

Non-Technical Summary: Organic processors currently rely on high temperature as the sole processing option for the pasteurization / sterilization of juices. However, the thermal processing of fruit juices and fruit concentrates is known to affect nutrient content (e.g., loss of thermo-labile vitamins B1, B2, A), antioxidant capacity, and/or organoleptic properties (e.g., flavor, cloudiness, color) depending on the specific product. The overall goal of this Research and Extension Planning Proposal is to assess the critical needs and potential impact of a systems-based comprehensive proposal on the application of nonthermal technologies for the processing of safe and high quality organic fruit juices. Specific objectives include: (1) Survey of Juice processors and assessment of their knowledge and attitudes towards nonthermal technologies, (2) Design commodity-specific safety and quality experiments and confirm the feasibility for coordinating multi-institution experiments, (3) Integrate a steering committee to determine the specific key elements for success including safety, quality, and cost, (4) Submit a proposal to USDA-NIFA-Organic Agriculture Research and Extension Initiative in 2011. This one year proposal is designed to actively involve organic processors on nonthermal technologies. To achieve these objectives, funds will be used to organize (a) two strategic meetings (06/2010, 11/2010) and (b) a feasibility experiment, where a single source juice will be processed by the various institutions involved in this project. This is a multi-institutional team with expertise on nonthermal technologies including high pressure homogenization, high hydrostatic pressure, UV light, and plasma processing. The team has also extensive expertise on microbiology and sensory evaluation of fruit juices, engineering and processing operations, and outreach and education. <P> Approach: Many natural antimicrobials are small molecular weight (<400 Da) low solubility molecules. These molecules, while effective in in vitro studies, are not successfully used in real food systems because they cannot be permanently incorporated into the aqueous microenvironment where microorganisms grow. Similarly, the food industry faces great difficulty avoiding phase separation of highly hydrophobic low molecular weight flavor compounds that are volatile or hydrophobic. This one year proof-of-concept research proposal was designed to demonstrate that (1) native casein micelles (50-250 nm) from bovine milk can be structurally modified (through dissociation re-aggregation) into newly formed nano-micelles (50-100 nm) that (2) can be used as carrying/delivery systems for small molecular weight hydrophobic flavors and antimicrobials in aqueous systems. The scale (nanometers) and nature (hydrophobicity) of the proposed interaction between molecule (antimicrobial or flavor) and carrier (casein nano-micelle), will promote the long term stability of the system and facilitate the delivery to the target site of action. Organic processors currently rely on high temperature as the sole processing option for the pasteurization / sterilization of juices. However, the thermal processing of fruit juices and fruit concentrates is known to affect nutrient content (e.g., loss of thermo-labile vitamins B1, B2, A), antioxidant capacity, and/or organoleptic properties (e.g., flavor, cloudiness, color) depending on the specific product. The overall goal of this Research and Extension Planning Proposal is to assess the critical needs and potential impact of a systems-based comprehensive proposal on the application of nonthermal technologies for the processing of safe and high quality organic fruit juices. Specific objectives include: (1) Survey of Juice processors and assessment of their knowledge and attitudes towards nonthermal technologies, (2) Design commodity-specific safety and quality experiments and confirm the feasibility for coordinating multi-institution experiments, (3) Integrate a steering committee to determine the specific key elements for success including safety, quality, and cost, (4) Submit a proposal to USDA-NIFA-Organic Agriculture Research and Extension Initiative in 2011. This one year proposal is designed to actively involve organic processors on nonthermal technologies. To achieve these objectives, funds will be used to organize (a) two strategic meetings (06/2010, 11/2010) and (b) a feasibility experiment, where a single source juice will be processed by the various institutions involved in this project. This is a multi-institutional team with expertise on nonthermal technologies including high pressure homogenization, high hydrostatic pressure, UV light, and plasma processing. The team has also extensive expertise on microbiology and sensory evaluation of fruit juices, engineering and processing operations, and outreach and education. The long term goal supporting this one year planning proposal is to build a comprehensive system-based approach to the subject of nonthermal technologies for the processing of organically grown safe fruits and vegetable juices. We intend to provide organic growers and processors with proven nonthermal processing technologies for the pasteurization / sterilization of high quality organic juices. This planning proposal intends to test a pilot experiment and to engage processors and growers in a steering committee to uncover specific needs, outcomes, and success criteria to be addressed in a subsequent three year comprehensive proposal on the use nonthermal technologies in juice processing.