Abstract: A novel method for isolating DNA from juices and ciders is described. This method is low cost and yield large quantities of highly purified DNA even though one uses a small quantity of juice or cider. A method for determining if a juice or cider is safe to consume and/or the quality of the juice or cider are also described. For these methods, one can perform qPCR on the DNA which can be obtained using the disclosed method or any other prior art method, and comparing the amount of DNA from microorganisms is present in the juice and/or cider to determine the safety and/or quality of the juice and/or cider. These methods work even if the liquid was pasteurized.

Abstract: Disclosed herein are viral vectors based on modifications of the Citrus Tristeza virus useful for transfecting citrus trees for beneficial purposes. Included in the disclosure are viral vectors including one or more gene cassettes that encode spinach defensin peptide(s). The gene cassettes are positioned at desirable locations on the viral genome so as to enable expression while preserving functionality of the virus. Also disclosed are methods of transfecting plants and plants transfected with viral vector embodiments.