title: Mitochondrial DNA Fragmentation to Monitor Processing Parameters in High Acid, Plant-Derived Foods.
abstract: Mitochondrial DNA (mtDNA) fragmentation was assessed in acidified foods. Using quantitative polymerase chain reaction, Ct values measured from fresh, fermented, pasteurized, and stored cucumber mtDNA were determined to be significantly different (P > 0.05) based on processing and shelf-life. This indicated that the combination of lower temperature thermal processes (hot-fill at 75 °C for 15 min) and acidified conditions (pH = 3.8) was sufficient to cause mtDNA fragmentation. In studies modeling high acid juices, pasteurization (96 °C, 0 to 24 min) of tomato serum produced Ct values which had high correlation to time-temperature treatment. Primers producing longer amplicons (approximately 1 kb) targeting the same mitochondrial gene gave greater sensitivity in correlating time-temperature treatments to Ct values. Lab-scale pasteurization studies using Ct values derived from the longer amplicon differentiated between heat treatments of tomato serum (95 °C for <2 min). MtDNA fragmentation was shown to be a potential new tool to characterize low temperature (<100 °C) high acid processes (pH < 4.6), nonthermal processes such as vegetable fermentation and holding times of acidified, plant-derived products.
authors.affiliation: Dept. of Food, Bioprocessing, and Nutrition Sciences, North Carolina State Univ, Raleigh, NC, 27695, U.S.A.
authors.forename: Jane M
authors.initials: JM
authors.lastname: Caldwell
authors.affiliation: USDA-Agriculture Research Service, SAA, Food Science Research Unit, 322 Schaub Hall-NCSU, Raleigh, NC, 27695, U.S.A.
authors.forename: Ilenys M
authors.initials: IM
authors.lastname: Pérez-Díaz
authors.affiliation: Dept. of Food, Bioprocessing, and Nutrition Sciences, North Carolina State Univ, Raleigh, NC, 27695, U.S.A.
authors.forename: Keith
authors.initials: K
authors.lastname: Harris
authors.affiliation: Prestage Dept. of Poultry Science, North Carolina State Univ, Raleigh, NC, 27695, U.S.A.
authors.forename: Hosni M
authors.initials: HM
authors.lastname: Hassan
authors.affiliation: Dept. of Food, Bioprocessing, and Nutrition Sciences, North Carolina State Univ, Raleigh, NC, 27695, U.S.A.
authors.forename: Josip
authors.initials: J
authors.lastname: Simunovic
authors.affiliation: Dept. of Food, Bioprocessing, and Nutrition Sciences, North Carolina State Univ, Raleigh, NC, 27695, U.S.A.
authors.forename: K P
authors.initials: KP
authors.lastname: Sandeep
mesh_terms: D000143:Acids; D001419:Bacteria / Q000254:growth & development*; D018553:Cucumis sativus / Q000235:genetics; D053938:DNA Fragmentation; D004272:DNA, Mitochondrial; D018744:DNA, Plant / Q000032:analysis; D005285:Fermentation; D005504:Food Analysis; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods*; D005638:Fruit; D050259:Genes, Mitochondrial; D017343:Genes, Plant; D006801:Humans; D006863:Hydrogen-Ion Concentration; D018551:Solanum lycopersicum / Q000235:genetics; D061352:Pasteurization; D010945:Plants, Edible / Q000235:genetics; D013696:Temperature; D014675:Vegetables
chemical_list: D000143:Acids; D004272:DNA, Mitochondrial; D018744:DNA, Plant
keywords: high-acid foods; mitochondrial DNA; quantitative PCR; thermal processing