PMID- 12076040
OWN - NLM
STAT- MEDLINE
DCOM- 20021007
LR  - 20190906
IS  - 0168-1605 (Print)
IS  - 0168-1605 (Linking)
VI  - 77
IP  - 1-2
DP  - 2002 Jul 25
TI  - Alicyclobacillus acidoterrestris spores as a target for Cupuacu (Theobroma 
      grandiflorum) nectar thermal processing: kinetic parameters and experimental 
      methods.
PG  - 71-81
AB  - The kinetic parameters of thermal inactivation of a spore former, 
      Alicyclobacillus acidoterrestris, in a tropical fruit nectar [25% of Cupuacu 
      (Theobroma grandiflorum) pulp and 15% sugar] were determined by the isothermal 
      method (IM), under batch heating, and by the paired equivalent isothermal 
      exposures (PEIE) method, under non-isothermal continuous conditions. The 
      isothermal experiments were repeated three times, every 4 months, with the same 
      spore suspension kept frozen between experiments. The aging of spores, under 
      frozen storage, seemed to produce a notorious increase in the z-value from 
      experiment to experiment: Experiment 1 (z = 7.8 +/- 2.6 degrees C, D(95 degrees 
      C) = 5.29 +/- 0.96 min), Experiment 2 (z = 22 +/- 5 degrees C, D(95 degrees C) = 
      5.99 +/- 0.63 min), and Experiment 3 (z =29 +/- 10 degrees C, D(95 degrees C) = 
      3.82 +/- 0.48 min). The evaluation of the kinetic parameters by the PEIE method 
      was carried out in parallel with Experiment 3, with the same aged spores, and the 
      results (z = 31 +/- 6 degrees C, D(95 degrees C) = 5.5 +/- 1.2 min) were close to 
      the ones obtained in this experiment. From this work, it seems that the PEIE 
      method can also be applied to evaluate the reduction parameters of a 
      spore-forming microorganism, and in a more realistic way, since the continuous 
      system eliminates the errors caused by come-up and cool-down times (CUT and CDT) 
      that are unavoidable in isothermal experiments. Therefore, when designing a 
      thermal process for a continuous system, the PEIE method should be used, or the 
      chances are that the process would be underdesigned, risking that the desired 
      level of spore inactivation would not be achieved. An optimization of the thermal 
      processing conditions was next performed for Cupuacu nectar, considering a 5D 
      reduction in A. acidoterrestris spores. If a pasteurization process is 
      considered, the conditions that ensure safety (9 min at 98 degrees C) only allow 
      a 55% retention of ascorbic acid (AA). If sterilization is considered, 8 s at 115 
      degrees C will ensure a safe product and retain 98.5% of the original ascorbic 
      acid. Therefore, if A. acidoterrestris is considered as the target microorganism, 
      the nectar should undergo an aseptic high temperature short time principle (HTST) 
      process to achieve a 5D reduction in this acidophilus spore former. However, if 
      the hot-fill-and-hold pasteurization process is preferred, the product should be 
      fortified with ascorbic acid.
FAU - Vieira, Margarida C
AU  - Vieira MC
AD  - Escola Superior de Tecnologia, Universidade do Algarve, Faro, Portugal. 
      mvieira@ualg.pt
FAU - Teixeira, Arthur A
AU  - Teixeira AA
FAU - Silva, Filipa M
AU  - Silva FM
FAU - Gaspar, Nelma
AU  - Gaspar N
FAU - Silva, Cristina L M
AU  - Silva CL
LA  - eng
PT  - Journal Article
PL  - Netherlands
TA  - Int J Food Microbiol
JT  - International journal of food microbiology
JID - 8412849
SB  - IM
MH  - Beverages/*microbiology
MH  - Colony Count, Microbial
MH  - Endospore-Forming Bacteria/*chemistry/*physiology
MH  - Food Handling
MH  - *Food Microbiology
MH  - Hot Temperature
MH  - Kinetics
MH  - Malvaceae/*microbiology
MH  - Spores, Bacterial/growth & development
MH  - Thermodynamics
EDAT- 2002/06/22 10:00
MHDA- 2002/10/09 04:00
CRDT- 2002/06/22 10:00
PHST- 2002/06/22 10:00 [pubmed]
PHST- 2002/10/09 04:00 [medline]
PHST- 2002/06/22 10:00 [entrez]
AID - S0168-1605(02)00043-0 [pii]
AID - 10.1016/s0168-1605(02)00043-0 [doi]
PST - ppublish
SO  - Int J Food Microbiol. 2002 Jul 25;77(1-2):71-81. doi: 
      10.1016/s0168-1605(02)00043-0.