Dynamics of Microbial Inactivation and Acrylamide Production in High-Temperature Heat Treatments

In food processes, optimizing processing parameters is crucial to ensure food safety, maximize food quality, and minimize the formation of potentially toxigenic compounds. This research focuses on the simultaneous impacts that severe heat treatments applied to food may have on the formation of harmful chemicals and on microbiological safety. The case studies analysed consider the appearance/synthesis of acrylamide after a sterilization heat treatment for two different foods: pureed potato and prune juice, using Geobacillus stearothermophilus as an indicator. It presents two contradictory situations: on the one hand, the application of a high-temperature treatment to a low acid food with G. stearothermophilus spores causes their inactivation, reaching food safety and stability from a microbiological point of view. On the other hand, high temperatures favour the appearance of acrylamide. In this way, the two objectives (microbiological safety and acrylamide production) are opposed. In this work, we analyse the effects of high-temperature thermal treatments (isothermal conditions between 120 and 135 °C) in food from two perspectives: microbiological safety/stability and acrylamide production. After analysing both objectives simultaneously, it is concluded that, contrary to what is expected, heat treatments at higher temperatures result in lower acrylamide production for the same level of microbial inactivation. This is due to the different dynamics and sensitivities of the processes at high temperatures. These results, as well as the presented methodology, can be a basis of analysis for decision makers to design heat treatments that ensure food safety while minimizing the amount of acrylamide (or other harmful substances) produced.

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Phosphoproteomic analysis of lettuce (Lactuca sativa L.) reveals starch and sucrose metabolism functions during bolting induced by high temperature

PLoS ONE ◽

10.1371/journal.pone.0244198 ◽

2020 ◽

Vol 15 (12) ◽

pp. e0244198

Author(s):

Xiaoxiao Qin ◽

Panpan Li ◽

Shaowei Lu ◽

Yanchuan Sun ◽

Lifeng Meng ◽

...

Keyword(s):

High Temperature ◽

High Temperatures ◽

Lactuca Sativa ◽

Molecular Mechanisms ◽

Soluble Sugar ◽

High Temperature Stress ◽

Temperature Treatment ◽

Sucrose Metabolism ◽

High Temperature Treatment ◽

Lactuca Sativa L

High temperatures induce early bolting in lettuce (Lactuca sativa L.), which decreases both quality and production. However, knowledge of the molecular mechanism underlying high temperature promotes premature bolting is lacking. In this study, we compared lettuce during the bolting period induced by high temperatures (33/25 °C, day/night) to which raised under controlled temperatures (20/13 °C, day/night) using iTRAQ-based phosphoproteomic analysis. A total of 3,814 phosphorylation sites located on 1,766 phosphopeptides from 987 phosphoproteins were identified after high-temperature treatment,among which 217 phosphoproteins significantly changed their expression abundance (116 upregulated and 101 downregulated). Most phosphoproteins for which the abundance was altered were associated with the metabolic process, with the main molecular functions were catalytic activity and transporter activity. Regarding the functional pathway, starch and sucrose metabolism was the mainly enriched signaling pathways. Hence, high temperature influenced phosphoprotein activity, especially that associated with starch and sucrose metabolism. We suspected that the lettuce shorten its growth cycle and reduce vegetative growth owing to changes in the contents of starch and soluble sugar after high temperature stress, which then led to early bolting/flowering. These findings improve our understanding of the regulatory molecular mechanisms involved in lettuce bolting.

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Microbiological Safety of Animal Wastes Processed by Physical Heat Treatment: An Alternative To Eliminate Human Pathogens in Biological Soil Amendments as Recommended by the Food Safety Modernization Act

Journal of Food Protection ◽

10.4315/0362-028x.jfp-16-181 ◽

2017 ◽

Vol 80 (3) ◽

pp. 392-405 ◽

Cited By ~ 2

Author(s):

Zhao Chen ◽

Xiuping Jiang

Keyword(s):

Food Safety ◽

Soil Amendments ◽

Heat Treatments ◽

Microbial Inactivation ◽

Animal Origin ◽

Treated Animal ◽

Human Pathogens ◽

Microbiological Safety ◽

Animal Wastes ◽

Physical Heat

ABSTRACT Animal wastes have high nutritional value as biological soil amendments of animal origin for plant cultivation in sustainable agriculture; however, they can be sources of some human pathogens. Although composting is an effective way to reduce pathogen levels in animal wastes, pathogens may still survive under certain conditions and persist in the composted products, which potentially could lead to fresh produce contamination. According to the U.S. Food and Drug Administration Food Safety Modernization Act, alternative treatments are recommended for reducing or eliminating human pathogens in raw animal manure. Physical heat treatments can be considered an effective method to inactivate pathogens in animal wastes. However, microbial inactivation in animal wastes can be affected by many factors, such as composition of animal wastes, type and physiological stage of the tested microorganism, and heat source. Following some current processing guidelines for physical heat treatments may not be adequate for completely eliminating pathogens from animal wastes. Therefore, this article primarily reviews the microbiological safety and economic value of physically heat-treated animal wastes as biological soil amendments.

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Screening and identification of genes affecting grain quality and spikelet fertility during high-temperature treatment in grain filling stage of rice

BMC Plant Biology ◽

10.1186/s12870-021-03056-9 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Jae-Ryoung Park ◽

Eun-Gyeong Kim ◽

Yoon-Hee Jang ◽

Kyung-Min Kim

Keyword(s):

High Temperature ◽

Candidate Genes ◽

High Temperatures ◽

Grain Quality ◽

Grain Filling ◽

Temperature Treatment ◽

Spikelet Fertility ◽

High Temperature Treatment ◽

Rice Varieties ◽

Grain Filling Stage

Abstract Background Recent temperature increases due to rapid climate change have negatively affected rice yield and grain quality. Particularly, high temperatures during right after the flowering stage reduce spikelet fertility, while interfering with sugar energy transport, and cause severe damage to grain quality by forming chalkiness grains. The effect of high-temperature on spikelet fertility and grain quality during grain filling stage was evaluated using a double haploid line derived from another culture of F1 by crossing Cheongcheong and Nagdong cultivars. Quantitative trait locus (QTL) mapping identifies candidate genes significantly associated with spikelet fertility and grain quality at high temperatures. Results Our analysis screened OsSFq3 that contributes to spikelet fertility and grain quality at high-temperature. OsSFq3 was fine-mapped in the region RM15749-RM15689 on chromosome 3, wherein four candidate genes related to the synthesis and decomposition of amylose, a starch component, were predicted. Four major candidate genes, including OsSFq3, and 10 different genes involved in the synthesis and decomposition of amylose and amylopectin, which are starch constituents, together with relative expression levels were analyzed. OsSFq3 was highly expressed during the initial stage of high-temperature treatment. It exhibited high homology with FLOURY ENDOSPERM 6 in Gramineae plants and is therefore expected to function similarly. Conclusion The QTL, major candidate genes, and OsSFq3 identified herein could be effectively used in breeding rice varieties to improve grain quality, while tolerating high temperatures, to cope with climate changes. Furthermore, linked markers can aid in marker-assisted selection of high-quality and -yield rice varieties tolerant to high temperatures.

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Enhanced inactivation of bacterial lipases and proteinases in whole milk by a modified ultra high temperature treatment

Journal of Dairy Research ◽

10.1017/s0022029900028636 ◽

1988 ◽

Vol 55 (3) ◽

pp. 373-380 ◽

Cited By ~ 5

Author(s):

Anthony R. Bucky ◽

Patrick R. Hayes ◽

David S. Robinson

Keyword(s):

Heat Treatment ◽

High Temperature ◽

Raw Milk ◽

Temperature Treatment ◽

Heat Treatments ◽

High Temperature Treatment ◽

Amino Groups ◽

Whole Milk ◽

Viable Bacteria ◽

Ultra High Temperature

SummaryCultures ofPseudomonasspp. strains P10, P12 and P15 grown in whole milk which contained ∼ 1 × 108viable bacteria ml−1demonstrated near linear increases in the concentration of short-chain free fatty acids and trichloroacetic acid soluble free amino groups at 20 °C, following either ultra high temperature (UHT) treatment (140 °C for 5 s) or dual heat treatments (140 °C followed by either 57, 60 or 65 °C). The dual heat treatments reduced the rates of lipolysis and proteolysis compared to the UHT treatment by up to 25-fold. The dual heat treatment utilizing 60 °C for 5 min also effectively limited both lipase and proteinase activities in raw milk culture samples which had contained either 6 × 106, 5 × 107or 1 × 108viable bacteria ml−1. In this system enzyme activities were reduced by up to 10-fold following dual heat treatment compared to UHT treatment alone.

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Effects of High Temperature Treatment on the Mechanical Properties of Basalt Fiber Reinforced Aluminous Composites

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.732.111 ◽

2015 ◽

Vol 732 ◽

pp. 111-114 ◽

Cited By ~ 1

Author(s):

Marcel Jogl ◽

Pavel Reiterman ◽

Ondřej Holčapek ◽

Jaroslava Koťátková

Keyword(s):

Mechanical Properties ◽

High Temperature ◽

Portland Cement ◽

High Temperatures ◽

Basalt Fiber ◽

Temperature Treatment ◽

High Temperature Treatment ◽

Experimental Program ◽

Aluminous Cement ◽

Properties Of Composites

Article presents the results of an experimental program aimed at investigating of the mechanical properties of composites based on aluminous cement with the addition of basalt fibres, which could be used in the manufacture of components resistant to high temperatures, including the retention of mechanical properties. Silica composites based on Portland cement and silica aggregates are not able to resist the effects of high temperatures [1], therefore a heat resistant mixtures in this experiment includes only components that are able to resist the effects of high temperatures.

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Screening and Identification of Genes Affecting Grain Quality and Spikelet Fertility During High-Temperature Treatment in Grain Filling Stage of Rice

10.21203/rs.3.rs-209217/v1 ◽

2021 ◽

Author(s):

Jae-Ryoung Park ◽

Eun-Gyeong Kim ◽

Yoon-Hee Jang ◽

Kyung-Min Kim

Keyword(s):

High Temperature ◽

Candidate Genes ◽

High Temperatures ◽

Grain Quality ◽

Grain Filling ◽

Temperature Treatment ◽

Spikelet Fertility ◽

High Temperature Treatment ◽

Rice Varieties ◽

Filling Stage

Abstract Background Recent temperature increases due to rapid climate change have negatively affected rice yield and grain quality. Particularly, high temperatures during rice filling stage from the flowering stage reduce spikelet fertility, while interfering with sugar energy transport, and cause severe damage to grain quality by forming chalkiness grains. The effect of high-temperature on spikelet fertility and grain quality during grain filling stage was evaluated using a double haploid line derived from anther culture of F1 by crossing Cheongcheong and Nagdong cultivars. Quantitative trait locus (QTL) mapping identifies candidate genes significantly associated with spikelet fertility and grain quality at high temperatures. Results Our analysis screened OsSFq3 that contributes to spikelet fertility and grain quality at high-temperature. OsSFq3 was fine-mapped in the region RM15749-RM15689 on chromosome 3, wherein four candidate genes related to the synthesis and decomposition of amylose, a starch component, were predicted. Four major candidate genes, including OsSFq3, and 10 different genes involved in the synthesis and decomposition of amylose and amylopectin, which are starch constituents, together with relative expression levels were analyzed. OsSFq3 was highly expressed during the initial stage of high-temperature treatment. It exhibited high homology with FLOURY ENDOSPERM 6 in Gramineae plants and is therefore expected to function similarly. Conclusion The QTL, major candidate genes, and OsSFq3 identified herein could be effectively used in breeding rice varieties to improve grain quality, while tolerating high temperatures, to cope with climate changes. Furthermore, linked markers can aid in marker-assisted selection of high-quality and -yield rice varieties tolerant to high temperatures.

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High Temperature Alters Sorbitol Metabolism in Pyrus pyrifolia Leaves and Fruit Flesh during Late Stages of Fruit Enlargement

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.138.6.443 ◽

2013 ◽

Vol 138 (6) ◽

pp. 443-451 ◽

Cited By ~ 13

Author(s):

Dongfeng Liu ◽

Junbei Ni ◽

Ruiyuan Wu ◽

Yuanwen Teng

Keyword(s):

High Temperature ◽

High Temperatures ◽

Fruit Quality ◽

Temperature Treatment ◽

Sorbitol Dehydrogenase ◽

High Temperature Treatment ◽

Pyrus Pyrifolia ◽

Mature Leaves ◽

Fruit Flesh ◽

Sorbitol Metabolism

Sorbitol is the main photosynthetic product and primary translocated carbohydrate in the Rosaceae and plays fundamental roles in plant growth, fruit quality, and osmotic stress adaptation. To investigate the effect of frequent high temperature during advanced fruit development on fruit quality of chinese sand pear [Pyrus pyrifolia (Burm. f.) Nakai], we analyzed sorbitol metabolism in mature leaves and fruit flesh of potted ‘Wonhwang’ pear trees. In mature leaves, sorbitol synthesis catalyzed by NADP+-dependent sorbitol-6-phosphate dehydrogenase (S6PDH) was repressed, while sorbitol utilization mainly catalyzed by NAD+-dependent sorbitol dehydrogenase (NAD+-SDH) and NADP+-dependent sorbitol dehydrogenase (NADP+-SDH) was higher than that before high-temperature treatment, which resulted in decreased sorbitol accumulation. In contrast, sucrose accumulation in mature leaves was significantly enhanced in response to high temperatures. In fruit flesh, accumulation of sorbitol and sucrose was increased at the time of harvest under high temperatures. Among sorbitol metabolic enzymes, only NAD+-SDH was sensitive to high temperature in fruit flesh, and significant decrease of NAD+-SDH activity indicated that the fruit sorbitol-uptake capacity was undermined under high temperatures. Transcription analysis revealed tissue-specific responses of NAD+-SDH genes (PpSDH1, PpSDH2, and PpSDH3) to high-temperature treatment. The NAD+-SDH activity and regulation of PpSDH1 and PpSDH3 were positively correlated in mature leaves. However, the downregulation of PpSDH1 and PpSDH2 was consistent with decreased enzyme activity in the fruit flesh. With regard to sorbitol transport, two sorbitol transporter genes (PpSOT1 and PpSOT2) were isolated, and downregulation of PpSOT2 expression in mature leaves indicated that the sorbitol-loading capability decreased under high-temperature conditions because of the limited sorbitol supply. These findings suggested that sorbitol metabolism responded differently in mature leaves and fruit flesh under high temperature, and that these dissimilar responses influenced fruit quality and may play important roles in adaptation to high temperatures.

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