1
|
Zhang S, Meenu M, Hu L, Ren J, Ramaswamy HS, Yu Y. Recent Progress in the Synergistic Bactericidal Effect of High Pressure and Temperature Processing in Fruits and Vegetables and Related Kinetics. Foods 2022; 11:foods11223698. [PMID: 36429290 PMCID: PMC9689688 DOI: 10.3390/foods11223698] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/13/2022] [Accepted: 11/16/2022] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Traditional thermal processing is a widely used method to ensure food safety. However, thermal processing leads to a significant decline in food quality, especially in the case of fruits and vegetables. To overcome this drawback, researchers are extensively exploring alternative non-thermal High-Pressure Processing (HPP) technology to ensure microbial safety and retaining the sensory and nutritional quality of food. However, HPP is unable to inactivate the spores of some pathogenic bacteria; thus, HPP in conjunction with moderate- and low-temperature is employed for inactivating the spores of harmful microorganisms. Scope and approach: In this paper, the inactivation effect of high-pressure and high-pressure thermal processing (HPTP) on harmful microorganisms in different food systems, along with the bactericidal kinetics model followed by HPP in certain food samples, have been reviewed. In addition, the effects of different factors such as microorganism species and growth stage, process parameters and pressurization mode, and food composition on microbial inactivation under the combined high-pressure and moderate/low-temperature treatment were discussed. KEY FINDINGS AND CONCLUSIONS The establishment of a reliable bactericidal kinetic model and accurate prediction of microbial inactivation will be helpful for industrial design, development, and optimization of safe HPP and HPTP treatment conditions.
Collapse
Affiliation(s)
- Sinan Zhang
- College of Biosystems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
- Key Laboratory of Equipment and Informatization in Environment Controlled Agriculture, Ministry of Agriculture, 866 Yuhangtang Road, Hangzhou 310058, China
| | - Maninder Meenu
- College of Biosystems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
- Key Laboratory of Equipment and Informatization in Environment Controlled Agriculture, Ministry of Agriculture, 866 Yuhangtang Road, Hangzhou 310058, China
| | - Lihui Hu
- College of Biosystems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
- Key Laboratory of Equipment and Informatization in Environment Controlled Agriculture, Ministry of Agriculture, 866 Yuhangtang Road, Hangzhou 310058, China
- Hangzhou Jiangnan Talent Service Co., Ltd., 681 Qingchun East Road, Hangzhou 310000, China
| | - Junde Ren
- College of Biosystems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
- Key Laboratory of Equipment and Informatization in Environment Controlled Agriculture, Ministry of Agriculture, 866 Yuhangtang Road, Hangzhou 310058, China
| | - Hosahalli S. Ramaswamy
- Department of Food Science and Agricultural Chemistry, McGill University, 21111 Lakeshore Road, St-Anne-de-Bellevue, QC H9X 3V9, Canada
| | - Yong Yu
- College of Biosystems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
- Key Laboratory of Equipment and Informatization in Environment Controlled Agriculture, Ministry of Agriculture, 866 Yuhangtang Road, Hangzhou 310058, China
- Correspondence: ; Tel.: +86-571-88982181
| |
Collapse
|
2
|
Wang TW, Hodge KT. Susceptibility of Rosaceous Pome and Stone Fruits to Postharvest Rot by Paecilomyces niveus. PLANT DISEASE 2022; 106:121-126. [PMID: 34445878 DOI: 10.1094/pdis-04-21-0855-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Paecilomyces rot of apples is a postharvest disease caused by Paecilomyces niveus, a problematic spoiling agent of fruit juices and derivatives. Processing fruits infected with Paecilomyces rot can lead to juices contaminated with P. niveus ascospores. These ascospores are heat resistant and may survive food processing and germinate in finished products. Because the fungus produces the mycotoxin patulin, juice spoilage by P. niveus is an important health hazard. Little is known about the disease biology and control mechanisms of this recently described postharvest disease. The range of fruit products contaminated by P. niveus and patulin led us to hypothesize that the host range of Paecilomyces rot is broader than previously thought. Following Koch's postulates, we determined that multiple untested rosaceous fruits and popular apple cultivars are susceptible to Paecilomyces rot infection and that these infected fruits contain significant levels of patulin. We also observed that two closely related food spoiling fungi, Paecilomyces fulvus and Paecilomyces variotti, were unable to infect, cause symptoms in, or grow in wounded fruits. Therefore, we challenge the assumption that P. niveus spoilage inoculum is introduced to foods solely through environmental sources, and we show that other economically important rosaceous fruits, peaches, pears, sweet cherries, and sour cherries, are susceptible to infection and can also be sources of spoilage inoculum. Our results highlight the unique abilities of P. niveus to infect a variety of fruits, produce patulin, and form resistant spores capable of spoiling normally shelf-stable products.
Collapse
Affiliation(s)
- Tristan W Wang
- Section of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853
| | - Kathie T Hodge
- Section of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853
| |
Collapse
|
3
|
A modified Weibull model for design of oscillated high hydrostatic pressure processes. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.111118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
4
|
Pinto CA, Moreira SA, Fidalgo LG, Inácio RS, Barba FJ, Saraiva JA. Effects of high-pressure processing on fungi spores: Factors affecting spore germination and inactivation and impact on ultrastructure. Compr Rev Food Sci Food Saf 2020; 19:553-573. [PMID: 33325178 DOI: 10.1111/1541-4337.12534] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 12/10/2019] [Accepted: 12/16/2019] [Indexed: 12/12/2022]
Abstract
Food contamination with heat-resistant fungi (HRF), and their spores, is a major issue among fruit processors, being frequently found in fruit juices and concentrates, among other products, leading to considerable economic losses and food safety issues. Several strategies were developed to minimize the contamination with HRF, with improvements from harvesting to the final product, including sanitizers and new processing techniques. Considering consumers' demands for minimally processed, fresh-like food products, nonthermal food-processing technologies, such as high-pressure processing (HPP), among others, are emerging as alternatives to the conventional thermal processing techniques. As no heat is applied to foods, vitamins, proteins, aromas, and taste are better kept when compared to thermal processes. Nevertheless, HPP is only able to destroy pathogenic and spoilage vegetative microorganisms to levels of pertinence for food safety, while bacterial spores remain. Regarding HRF spores (both ascospores and conidiospores), these seem to be more pressure-sensible than bacterial spores, despite a few cases, such as the ascospores of Byssochlamys spp., Neosartorya spp., and Talaromyces spp. that are resistant to high pressures and high temperatures, requiring the combination of both variables to be inactivated. This review aims to cover the literature available concerning the effects of HPP at room-like temperatures, and its combination with high temperatures, and high-pressure cycling, to inactivate fungi spores, including the main factors affecting spores' resistance to high-pressure, such as pH, water activity, nutritional composition of the food matrix and ascospore age, as well as the changes in the spore ultrastructure, and the parameters to consider regarding their inactivation by HPP.
Collapse
Affiliation(s)
- Carlos A Pinto
- QOPNA & LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, Aveiro, Portugal
| | - Sílvia A Moreira
- QOPNA & LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, Aveiro, Portugal
| | - Liliana G Fidalgo
- QOPNA & LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, Aveiro, Portugal.,Escola Superior Agrária, Instituto Politécnico de Beja, Beja, Portugal
| | - Rita S Inácio
- QOPNA & LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, Aveiro, Portugal
| | - Francisco J Barba
- Area de Nutrición y Bromatología, Facultat de Farmàcia, Universitat de València, Burjassot, Spain
| | - Jorge A Saraiva
- QOPNA & LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, Aveiro, Portugal
| |
Collapse
|
5
|
Dijksterhuis J, Meijer M, van Doorn T, Samson R, Rico-Munoz E. Inactivation of stress-resistant ascospores of Eurotiales by industrial sanitizers. Int J Food Microbiol 2018; 285:27-33. [DOI: 10.1016/j.ijfoodmicro.2018.06.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 06/18/2018] [Accepted: 06/22/2018] [Indexed: 10/28/2022]
|
6
|
Evelyn, Silva FV. Resistance of Byssochlamys nivea and Neosartorya fischeri mould spores of different age to high pressure thermal processing and thermosonication. J FOOD ENG 2017. [DOI: 10.1016/j.jfoodeng.2017.01.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
7
|
Alicyclobacillus acidoterrestris spore inactivation by high pressure combined with mild heat: Modeling the effects of temperature and soluble solids. Food Control 2017. [DOI: 10.1016/j.foodcont.2016.08.034] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
8
|
Yang C, Bian G, Yang H, Zhang X, Chen L, Wang J. Development of High Hydrostatic Pressure Applied in Pathogen Inactivation for Plasma. PLoS One 2016; 11:e0161775. [PMID: 27561010 PMCID: PMC4999174 DOI: 10.1371/journal.pone.0161775] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 08/11/2016] [Indexed: 01/20/2023] Open
Abstract
High hydrostatic pressure has been used to inactivate pathogens in foods for decades. There is a great potential to adapt this technology to inactivate pathogens in plasma and derivatives. To better evaluate the potential of this method, pathogen inoculated plasma samples were pressurized under different pressure application modes and temperatures. The inactivation efficacy of pathogens and activities of plasma proteins were monitored after treatment. The CFUs of E.coli was examined as the indicator of the inactivation efficiency. The factor V and VIII were chosen as the indicator of the plasma function. Preliminary experiments identified optimized treatment conditions: 200-250MPa, with 5×1 minute multi-pulsed high pressure at near 0°C (ice-water bath). Under this conditions, the inactivation efficacy of EMCV was >8.5log. The CFUs of E. coli were reduced by 7.5log, B. cereus were 8log. However, PPV and S. aureus cannot be inactivated efficiently. The activities of factor II, VII, IX, X, XI, XII, fibrinogen, IgG, IgM stayed over 95% compared to untreated. Factor V and VIII activity was maintained at 46–63% and 77–82%, respectively.
Collapse
Affiliation(s)
- Chunhui Yang
- Institute of Blood Transfusion, Chinese Academy of Medical Sciences (CAMS) & Peking Union Medical College (PUMC), Chengdu, Sichuan, China
| | - Guohui Bian
- Institute of Blood Transfusion, Chinese Academy of Medical Sciences (CAMS) & Peking Union Medical College (PUMC), Chengdu, Sichuan, China
| | - Hong Yang
- Institute of Blood Transfusion, Chinese Academy of Medical Sciences (CAMS) & Peking Union Medical College (PUMC), Chengdu, Sichuan, China
| | - Xinmin Zhang
- Zhengzhou Feilong medic devices Co., Ltd, Zhengzhou, Henan, China
| | - Limin Chen
- Institute of Blood Transfusion, Chinese Academy of Medical Sciences (CAMS) & Peking Union Medical College (PUMC), Chengdu, Sichuan, China
| | - Jingxing Wang
- Institute of Blood Transfusion, Chinese Academy of Medical Sciences (CAMS) & Peking Union Medical College (PUMC), Chengdu, Sichuan, China
- * E-mail:
| |
Collapse
|
9
|
Wyatt TT, Wösten HAB, Dijksterhuis J. Fungal spores for dispersion in space and time. ADVANCES IN APPLIED MICROBIOLOGY 2016; 85:43-91. [PMID: 23942148 DOI: 10.1016/b978-0-12-407672-3.00002-2] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Spores are an integral part of the life cycle of the gross majority of fungi. Their morphology and the mode of formation are both highly variable among the fungi, as is their resistance to stressors. The main aim for spores is to be dispersed, both in space, by various mechanisms or in time, by an extended period of dormancy. Some fungal ascospores belong to the most stress-resistant eukaryotic cells described to date. Stabilization is a process in which biomolecules and complexes thereof are protected by different types of molecules against heat, drought, or other molecules. This review discusses the most important compounds that are known to protect fungal spores and also addresses the biophysics of cell protection. It further covers the phenomena of dormancy, breaking of dormancy, and early germination. Germination is the transition from a dormant cell toward a vegetative cell and includes a number of specific changes. Finally, the applied aspects of spore biology are discussed.
Collapse
Affiliation(s)
- Timon T Wyatt
- Department of Applied and Industrial Mycology, CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, Utrecht, The Netherlands
| | | | | |
Collapse
|
10
|
Evelyn, Kim H, Silva F. Modeling the inactivation of Neosartorya fischeri ascospores in apple juice by high pressure, power ultrasound and thermal processing. Food Control 2016. [DOI: 10.1016/j.foodcont.2015.06.033] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
11
|
Inactivation of Byssochlamys nivea ascospores in strawberry puree by high pressure, power ultrasound and thermal processing. Int J Food Microbiol 2015; 214:129-136. [PMID: 26280285 DOI: 10.1016/j.ijfoodmicro.2015.07.031] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Revised: 07/08/2015] [Accepted: 07/30/2015] [Indexed: 11/20/2022]
Abstract
Byssochlamys nivea is a mold that can spoil processed fruit products and produce mycotoxins. In this work, high pressure processing (HPP, 600 MPa) and power ultrasound (24 kHz, 0.33 W/mL; TS) in combination with 75°C for the inactivation of four week old B. nivea ascospores in strawberry puree for up to 30 min was investigated and compared with 75°C thermal processing alone. TS and thermal processing can activate the mold ascospores, but HPP-75°C resulted in 2.0 log reductions after a 20 min process. For a 10 min process, HPP-75°C was better than 85°C alone in reducing B. nivea spores (1.4 vs. 0.2 log reduction), demonstrating that a lower temperature in combination with HPP is more effective for spore inactivation than heat alone at a higher temperature. The ascospore inactivation by HPP-thermal, TS and thermal processing was studied at different temperatures and modeled. Faster inactivation was achieved at higher temperatures for all the technologies tested, indicating the significant role of temperature in spore inactivation, alone or combined with other physical processes. The Weibull model described the spore inactivation by 600 MPa HPP-thermal (38, 50, 60, 75°C) and thermal (85, 90°C) processing, whereas the Lorentzian model was more appropriate for TS treatment (65, 70, 75°C). The models obtained provide a useful tool to design and predict pasteurization processes targeting B. nivea ascospores.
Collapse
|
12
|
Wyatt TT, Gerwig GJ, Kamerling JP, Wösten HA, Dijksterhuis J. Structural analysis of novel trehalose-based oligosaccharides from extremely stress-tolerant ascospores of Neosartorya fischeri (Aspergillus fischeri). Carbohydr Res 2015; 411:49-55. [DOI: 10.1016/j.carres.2015.04.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 04/08/2015] [Accepted: 04/10/2015] [Indexed: 11/29/2022]
|
13
|
Abstract
Multi-pulsed high hydrostatic pressure (mpHHP) treatment of foods has been investigated for more than two decades. It was reported that the mpHHP treatment, with few exceptions, is more effective than the classical or single-pulsed HHP (spHHP) treatment for inactivation of microorganisms in fruit juice, dairy products, liquid whole egg, meat products, and sea foods. Moreover, the mpHHP treatment could be also used to inactivate enzymes in foods and to increase the shelf-life of foods. The effects of the mpHHP treatment of foods are summarized and the differences between the mpHHP and spHHP are also emphasized.
Collapse
|
14
|
|
15
|
HIREMATH NIKHILD, RAMASWAMY HOSAHALLIS. HIGH-PRESSURE DESTRUCTION KINETICS OF SPOILAGE AND PATHOGENIC MICROORGANISMS IN MANGO JUICE. J FOOD PROCESS PRES 2011. [DOI: 10.1111/j.1745-4549.2011.00559.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
16
|
Microbiological food safety assessment of high hydrostatic pressure processing: A review. Lebensm Wiss Technol 2011. [DOI: 10.1016/j.lwt.2010.11.001] [Citation(s) in RCA: 259] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
17
|
Fundamentals and Applications of High Pressure Processing to Foods. ACTA ACUST UNITED AC 2010. [DOI: 10.1201/9780203997277.ch8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
18
|
Chang SS, Han A, Reyes-De-Corcuera J, Powers J, Kang DH. Evaluation of steam pasteurization in controllingSalmonellaserotype Enteritidis on raw almond surfaces. Lett Appl Microbiol 2010; 50:393-8. [DOI: 10.1111/j.1472-765x.2010.02809.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
19
|
Ferreira EHDR, Rosenthal A, Calado V, Saraiva J, Mendo S. Byssochlamys nivea inactivation in pineapple juice and nectar using high pressure cycles. J FOOD ENG 2009. [DOI: 10.1016/j.jfoodeng.2009.06.053] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
20
|
Tribst AA, Franchi MA, Cristianini M, De Massaguer PR. Inactivation of Aspergillus niger in Mango Nectar by High-Pressure Homogenization Combined with Heat Shock. J Food Sci 2009; 74:M509-14. [DOI: 10.1111/j.1750-3841.2009.01370.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
21
|
Morales P, Calzada J, Rodríguez B, De Paz M, Nuñez M. Inactivation ofSalmonellaEnteritidis in Chicken Breast Fillets by Single-Cycle and Multiple-Cycle High Pressure Treatments. Foodborne Pathog Dis 2009; 6:577-81. [DOI: 10.1089/fpd.2008.0218] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
| | | | | | | | - Manuel Nuñez
- Dpto. Tecnología de Alimentos, INIA, Madrid, Spain
| |
Collapse
|
22
|
Neetoo H, Ye M, Chen H. Factors affecting the efficacy of pressure inactivation of Escherichia coli O157:H7 on alfalfa seeds and seed viability. Int J Food Microbiol 2009; 131:218-23. [DOI: 10.1016/j.ijfoodmicro.2009.02.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2008] [Revised: 02/19/2009] [Accepted: 02/28/2009] [Indexed: 10/21/2022]
|
23
|
Chapman B, Winley E, Fong A, Hocking A, Stewart C, Buckle K. Ascospore inactivation and germination by high pressure processing is affected by ascospore age. INNOV FOOD SCI EMERG 2007. [DOI: 10.1016/j.ifset.2007.04.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
24
|
Black EP, Setlow P, Hocking AD, Stewart CM, Kelly AL, Hoover DG. Response of Spores to High-Pressure Processing. Compr Rev Food Sci Food Saf 2007. [DOI: 10.1111/j.1541-4337.2007.00021.x] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
25
|
|
26
|
Dijksterhuis J, Samson RA. Activation of ascospores by novel food preservation techniques. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2006; 571:247-60. [PMID: 16408607 DOI: 10.1007/0-387-28391-9_17] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Jan Dijksterhuis
- Department of Applied Research and Services, Centraalbureau voor Schimmelcultures, Fungal Biodiversity Centre, Utrecht, The Netherlands.
| | | |
Collapse
|
27
|
Dijksterhuis J, Teunissen PGM. Dormant ascospores of Talaromyces macrosporus are activated to germinate after treatment with ultra high pressure. J Appl Microbiol 2004; 96:162-9. [PMID: 14678170 DOI: 10.1046/j.1365-2672.2003.02133.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS Ascospores of Talaromyces macrosporus are constitutively dormant and germinate after a strong external shock, classically a heat treatment. This fungus is used as a model system to study heat resistance leading to food spoilage after pasteurization. This study evaluates the effect of high pressure on the germination behaviour of these spores. METHODS AND RESULTS Ascospore containing bags were subjected to ultra high pressure and spores were plated out on agar surfaces. Untreated suspensions showed invariably very low germination. Increased germination of ascospores occurred after short treatments at very high pressure (between 400 and 800 MPa). Activation is partial compared with heat activation and did not exceed 6.9% (65 times that of untreated suspensions) of the spore population. Maximum activation was attained shortly (10 s-3 min) after the pressure was applied and accompanied by cell wall deformations as judged by scanning electron microscopy. The spores observed in this study were harvested from cultures that were 39-58 days old. The maturity of spores at similar developmental stages was measured by assessing the heat resistance of ascospores. Between 20 and 40 days heat resistance increased 2.4-fold, but only an additional increase of 1.3-fold was observed at later stages (40-67 days). CONCLUSIONS Our investigations show that high pressure constitutes a second type of shock that can activate heat-resistant ascospores to germinate. Activation is maximal after very short treatments and accompanied with changes in the cell wall structure. High-pressure activation is not the result of immaturity of the ascospores. SIGNIFICANCE AND IMPACT OF THE STUDY These observations are relevant for the application of high pressure as a novel pasteurization method.
Collapse
Affiliation(s)
- J Dijksterhuis
- Agrotechnological Research Institute (ATO), Wageningen, The Netherlands.
| | | |
Collapse
|
28
|
Reyns KMFA, Veraverbeke EA, Michiels CW. Activation and inactivation of Talaromyces macrosporus ascospores by high hydrostatic pressure. J Food Prot 2003; 66:1035-42. [PMID: 12801006 DOI: 10.4315/0362-028x-66.6.1035] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The effect of high hydrostatic pressure treatment (with pressures of up to 700 MPa) on Talaromyces macrosporus ascospores was investigated. At 20 degrees C, pressures of > or = 200 MPa induced the activation and germination of dormant ascospores, as indicated by increased colony counts for ascospore suspensions after pressure treatment and the appearance of germination vesicles and tubes. Pressures of > 400 MPa additionally sensitized the ascospores to subsequent heat treatment. At pressures of > 500 MPa, activation occurred in a few minutes but was followed by inactivation with longer exposure. However, even with the most extreme pressure treatment, a fraction of the ascospore population appeared to resist both activation and inactivation, and the maximal achievable reduction of ascospores was on the order of 3.0 log10 units. Pressure-induced ascospore activation at 400 MPa was temperature dependent, with minimum activation at 30 to 50 degrees C and > or = 10-fold higher activation levels at 10 to 20 degrees C and at 60 degrees C, but it was not particularly pH dependent over a pH range of 3.0 to 6.0. Pressure inactivation at 600 MPa, in contrast, was pH dependent, with the inactivation level being 10-fold higher at pH 6.0 than at pH 3.0. Observation of pressure-treated and subsequently dried spores with the use of light and scanning electron microscopy revealed a collapse of the spore structure, indicating a loss of the spore wall barrier properties. Finally, pressure treatment sensitized T. macrosporus ascospores to cell wall lytic enzymes.
Collapse
Affiliation(s)
- Kristien M F A Reyns
- Laboratory of Food Microbiology, Katholieke Universiteit Leuven, Kasteelpark Arenberg 22, B-3001 Leuven, Belgium
| | | | | |
Collapse
|
29
|
Palou E, Hernández-Salgado C, López-Malo A, Barbosa-Cánovas G, Swanson B, Welti-Chanes J. High pressure-processed guacamole. INNOV FOOD SCI EMERG 2000. [DOI: 10.1016/s1466-8564(99)00002-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|