title: Thermal inactivation of Salmonella enteritidis PT 30 in almond kernels as influenced by water activity.
abstract: Salmonellosis outbreaks related to consumption of raw almonds have encouraged the scientific community to study the inactivation kinetics of pathogens in this dry commodity. However, the low moisture content of the product presents a challenge for thermal control, because the time required  to achieve the desired thermal inactivation of microorganisms increases sharply with reduced moisture content and water activity. In this study, we explored and modeled the heat inactivation of Salmonella enterica serovar Enteritidis PT 30 in almond cultivar 'Nonpareil' kernel flour  at four water activity (a(w)) values (0.601, 0.720, 0.888, and 0.946) using four temperatures for each a(w). The results showed that the inactivation was well fitted by both Weibull distribution (R(2) = 0.93 to 1.00) and first-order kinetics (R(2)  = 0.82 to 0.96). At higher a(w) values, the rate of inactivation increased and less time was needed to achieve the required population reduction. These results suggest that, to avoid deterioration of product quality, shorter process times at lower temperatures may be used to achieve  desired inactivation levels of Salmonella Enteritidis PT 30 by simply increasing the moisture content of almonds. These goals could be achieved with the use of existing procedures already practiced by the food industry, such as washing or prewetting scalding before heat inactivation.
authors: Departamento de Ingeniería Química, Alimentos y Ambiental, Universidad de las Américas Puebla Santa Catarina Mártir, Cholula, Puebla 72810, Mexico.
authors: Rossana
authors: R
authors: Villa-Rojas
authors: Juming
authors: J
authors: Tang
authors: Shaojin
authors: S
authors: Wang
authors: Mengxiang
authors: M
authors: Gao
authors: Dong-Hyun
authors: DH
authors: Kang
authors: Jae-Hyung
authors: JH
authors: Mah
authors: Peter
authors: P
authors: Gray
authors: Maria Elena
authors: ME
authors: Sosa-Morales
authors: Aurelio
authors: A
authors: López-Malo
mesh_terms: D001434:Bacteriophage Typing; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004196:Disease Outbreaks; D005506:Food Contamination / Q000032:analysis; D005511:Food Handling / Q000379:methods; D005516:Food Microbiology; D059022:Food Safety; D006358:Hot Temperature; D006801:Humans; D007700:Kinetics; D008954:Models, Biological; D027861:Prunus / Q000382:microbiology*; D012307:Risk Factors; D012478:Salmonella Food Poisoning / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D012477:Salmonella enteritidis / Q000254:growth & development* / Q000378:metabolism; D014867:Water / Q000378:metabolism*
chemical_list: D014867:Water