東華大學圖書館 |

Predicting Initial Transformation Products of Food-Based Bio-Polymers and -Molecules During Food Disinfection.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Predicting Initial Transformation Products of Food-Based Bio-Polymers and -Molecules During Food Disinfection./
作者:	Simpson, Adam MichaelAnthony.
面頁冊數:	1 online resource (185 pages)
附註:	Source: Dissertations Abstracts International, Volume: 84-04, Section: B.
Contained By:	Dissertations Abstracts International84-04B.
標題:	By products. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=29408081click for full text (PQDT)
ISBN:	9798352648698

Predicting Initial Transformation Products of Food-Based Bio-Polymers and -Molecules During Food Disinfection.
Simpson, Adam MichaelAnthony.

Predicting Initial Transformation Products of Food-Based Bio-Polymers and -Molecules During Food Disinfection. - 1 online resource (185 pages)

Source: Dissertations Abstracts International, Volume: 84-04, Section: B.

Thesis (Ph.D.)--Stanford University, 2022.

Includes bibliographical references

Starting in the early 1900s, chlorinating potable water supplies dramatically reduced the incidence of waterborne diseases. However, in the 1970s, analytical chemists discov-ered trihalomethanes (THMs) as byproducts of chlorination reactions with natural organic matter (NOM) in drinking water. Although greater than 600 disinfection byproducts (DBPs) have since been characterized in drinking water, regulations continue to focus on THMS and haloacetic acids (HAAs). With recent toxicological studies demonstrating that other DBPs have orders of magnitude higher toxic potencies than THMs and HAAs, cur-rent research has shifted to focus on characterizing newer classes of DBPs that could con-tribute to toxicity. However, these investigations remain arduous due to the difficulty in characterizing DBP precursors found in NOM. Nonetheless, research using amino acids and other model precursors demonstrates that yields of THMs and HAAs are < 1% due to the difficulty of breaking carbon-carbon bonds to liberate these 1-2 carbon byproducts from larger precursor structures. Identifying the higher-yield initial products of chlorine addition to components of NOM has been difficult because the structures of these NOM compo-nents are unclear. With regards to food, pathogenic outbreaks are still prevalent. It is estimated that foodborne pathogen outbreaks now exceed those in drinking water. Free chlorine is the most widely used food disinfectant. Although chlorine exposures required for food wash-ing in packaging facilities have not yet been codified, chlorine doses (50-200 mg/L as Cl2) and precursor concentrations (solid food) are much higher than encountered in drinking water. Although research on the formation of DBPs in chemically disinfected foods has been published, these studies tend to focus on the same low-yield DBPs (e.g., THMs) that are the focus of drinking water research. They are unlikely to represent an exposure con-cern in food because they tend to partition to the washwater rather than the food. In con-trast, the structures of the biomolecular precursors in food (e.g., the amino acids constitut-ing protein and the fatty acids constituting lipids) are well-characterized. Instead, I argue that the initial products of chlorine addition to amino acids and fatty acids will be of greater importance for consumer exposure since they will form at high yield and remain bound in food matrices. This dissertation introduces (chapter 2) the reader to: the necessity of food disinfec-tion, food processing, mechanisms of disinfection by chlorine and ozone, and the study of food disinfection byproducts as the backdrop for understanding the subsequent chapters. Following this introduction, the dissertation uses the formation of chlorotyrosines from protein-bound tyrosines in produce as a model for the initial chlorine addition products to proteins within produce and demonstrates their importance as toxicity drivers relative to the 1-2 carbon DBPs of current research interest (chapter 3). Finally, this work (chapter 4) shows the formation of fatty acid chlorohydrins from lipid-bound fatty acids as a model for the initial chlorine addition products to lipids inside chlorine-treated produce. Overall, this dissertation shows the complexity of food disinfection byproduct research, and the need for further investigation of these contaminants as potentially dominant components of the over-all toxic exposures.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2023

Mode of access: World Wide Web

ISBN: 9798352648698Subjects--Topical Terms:

3564729
By products.
Index Terms--Genre/Form:

542853
Electronic books.

Predicting Initial Transformation Products of Food-Based Bio-Polymers and -Molecules During Food Disinfection.
LDR:04833nmm a2200409K 4500 001 2359853
005 20230917195305.5
006 m o d
007 cr mn ---uuuuu
008 241011s2022 xx obm 000 0 eng d
020 $a 9798352648698
035 $a (MiAaPQ)AAI29408081
035 $a (MiAaPQ)STANFORDmq066vq4290
035 $a AAI29408081
040 $a MiAaPQ $b eng $c MiAaPQ $d NTU
100 1 $a Simpson, Adam MichaelAnthony. $3 3700466
245 1 0 $a Predicting Initial Transformation Products of Food-Based Bio-Polymers and -Molecules During Food Disinfection.
264 0 $c 2022
300 $a 1 online resource (185 pages)
336 $a text $b txt $2 rdacontent
337 $a computer $b c $2 rdamedia
338 $a online resource $b cr $2 rdacarrier
500 $a Source: Dissertations Abstracts International, Volume: 84-04, Section: B.
500 $a Advisor: Mitch, William A.
502 $a Thesis (Ph.D.)--Stanford University, 2022.
504 $a Includes bibliographical references
520 $a Starting in the early 1900s, chlorinating potable water supplies dramatically reduced the incidence of waterborne diseases. However, in the 1970s, analytical chemists discov-ered trihalomethanes (THMs) as byproducts of chlorination reactions with natural organic matter (NOM) in drinking water. Although greater than 600 disinfection byproducts (DBPs) have since been characterized in drinking water, regulations continue to focus on THMS and haloacetic acids (HAAs). With recent toxicological studies demonstrating that other DBPs have orders of magnitude higher toxic potencies than THMs and HAAs, cur-rent research has shifted to focus on characterizing newer classes of DBPs that could con-tribute to toxicity. However, these investigations remain arduous due to the difficulty in characterizing DBP precursors found in NOM. Nonetheless, research using amino acids and other model precursors demonstrates that yields of THMs and HAAs are < 1% due to the difficulty of breaking carbon-carbon bonds to liberate these 1-2 carbon byproducts from larger precursor structures. Identifying the higher-yield initial products of chlorine addition to components of NOM has been difficult because the structures of these NOM compo-nents are unclear. With regards to food, pathogenic outbreaks are still prevalent. It is estimated that foodborne pathogen outbreaks now exceed those in drinking water. Free chlorine is the most widely used food disinfectant. Although chlorine exposures required for food wash-ing in packaging facilities have not yet been codified, chlorine doses (50-200 mg/L as Cl2) and precursor concentrations (solid food) are much higher than encountered in drinking water. Although research on the formation of DBPs in chemically disinfected foods has been published, these studies tend to focus on the same low-yield DBPs (e.g., THMs) that are the focus of drinking water research. They are unlikely to represent an exposure con-cern in food because they tend to partition to the washwater rather than the food. In con-trast, the structures of the biomolecular precursors in food (e.g., the amino acids constitut-ing protein and the fatty acids constituting lipids) are well-characterized. Instead, I argue that the initial products of chlorine addition to amino acids and fatty acids will be of greater importance for consumer exposure since they will form at high yield and remain bound in food matrices. This dissertation introduces (chapter 2) the reader to: the necessity of food disinfec-tion, food processing, mechanisms of disinfection by chlorine and ozone, and the study of food disinfection byproducts as the backdrop for understanding the subsequent chapters. Following this introduction, the dissertation uses the formation of chlorotyrosines from protein-bound tyrosines in produce as a model for the initial chlorine addition products to proteins within produce and demonstrates their importance as toxicity drivers relative to the 1-2 carbon DBPs of current research interest (chapter 3). Finally, this work (chapter 4) shows the formation of fatty acid chlorohydrins from lipid-bound fatty acids as a model for the initial chlorine addition products to lipids inside chlorine-treated produce. Overall, this dissertation shows the complexity of food disinfection byproduct research, and the need for further investigation of these contaminants as potentially dominant components of the over-all toxic exposures.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2023
538 $a Mode of access: World Wide Web
650 4 $a By products. $3 3564729
650 4 $a Pathogens. $3 3540520
650 4 $a Cod. $3 3685254
650 4 $a Meat. $3 660277
650 4 $a Food contamination & poisoning. $3 3562624
650 4 $a Biopolymers. $3 622162
650 4 $a Salmonella. $3 879055
650 4 $a Water treatment. $3 3683746
650 4 $a Cytotoxicity. $3 3682273
650 4 $a Prevention. $3 1375183
650 4 $a Carbohydrates. $3 522687
650 4 $a Epidemics. $3 588395
650 4 $a Drinking water. $3 605014
650 4 $a Fruits. $3 3680926
650 4 $a Potassium. $3 3562093
650 4 $a Lipids. $3 558980
650 4 $a Irrigation. $3 778786
650 4 $a Harvest. $3 3559359
650 4 $a Diaspora. $2 gtt $3 854148
650 4 $a Vegetables. $3 818721
650 4 $a Disease control. $3 3562653
650 4 $a Fish. $3 3564374
650 4 $a Agronomy. $3 2122783
650 4 $a Animal sciences. $3 3174829
650 4 $a Cellular biology. $3 3172791
650 4 $a Environmental engineering. $3 548583
650 4 $a Epidemiology. $3 568544
650 4 $a Food science. $3 3173303
650 4 $a Medicine. $3 641104
650 4 $a Polymer chemistry. $3 3173488
655 7 $a Electronic books. $2 lcsh $3 542853
690 $a 0285
690 $a 0475
690 $a 0379
690 $a 0775
690 $a 0766
690 $a 0359
690 $a 0564
690 $a 0495
710 2 $a ProQuest Information and Learning Co. $3 783688
710 2 $a Stanford University. $3 754827
773 0 $t Dissertations Abstracts International $g 84-04B.
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=29408081 $z click for full text (PQDT)