分析：許多麥麩 (麵筋，gluten）不耐受的美國人到了歐洲吃小麥製品平安無事 - dudaan

杜編提出的這個現象很有意思，我記得有網友在此也說過親身經曆。

美國的小麥和歐洲的小麥本身似乎沒有很大的區別，那麽在生產和加工環節可能是有區別的。杜編給出的鏈接中有個評論，提到美國烤麵包時用溴酸鉀，而歐洲不用。其評論原文如下：

 

Melodykanis

3/4/2019 8:37:23 AM

I would suggest this. Is it gluten intolerance, or are we adding an ingredient in the United States that is causing our digestive issues? My problem started 1 year ago. I feel very fortunate to have found that it isn't actually the gluten. It is the carcinogen "bromate". When I eat any wheat product that does not have bromate in it, I have no reaction. This carcinogen is not allowed in many countries including China???? The problem is that it is not required as a listed ingredient. Some of the places that I have found that do not use flour with bromate are Great Harvest Bread, and Panera Bread. I would suggest trying this. Then research, research, research. I buy pasta made in Italy, and make my own bakery items as much as possible. King Arthur flour is one of the brands that is not processed with Bromate. This epidemic is actually a poisoning. Is there any way to stop this???

 

查wiki，得知：

溴酸鉀是一個無機鹽，室溫下為無色晶體，分子式為KBrO₃。

其在發酵、醒發及焙烤工藝過程中起到一種氧化劑的作用，使用了溴酸鉀後的麵粉更白，製作的麵包能快速膨脹，更具有彈性和韌性，在焙烤業被認為是最好的麵粉改良劑之一。溴酸鉀有致癌性，現在已被許多國家（如歐盟）禁用，但在美國仍允許使用。溴酸鉀在足夠長的烘烤時間和溫度下會耗盡，但是如果在麵粉中添加的太多就會有殘留。

中華人民共和國衛生部於2005年5月30日發布《2005年第9號公告》稱，根據溴酸鉀危險性評估結果，決定自2005年7月1日起，取消溴酸鉀作為麵粉處理劑在小麥粉中使用。在此之前按照《食品添加劑使用衛生標準》（GB2760-1996）使用溴酸鉀的食品可以在產品保質期內繼續銷售。

 

對麵筋不耐受的主要機製是麵筋中的麥醇溶蛋白被消化分解產生的多肽進入體內引起過敏反應。在烘焙過程中，麥醇溶蛋白與麥麩中的穀蛋白通過二硫鍵形成膠聯產物，而溴酸鉀是氧化劑，減少了該反應的發生。雖然機理還不很清楚，我們也許可以這樣假設：

在烘焙過程中，容易產生過敏反應原的麥醇溶蛋白與穀蛋白形成膠聯產物，這使麥醇溶蛋白被消化分解成過敏原的機會降低。由於溴酸鉀的存在，這種膠聯反應受到阻礙，從而麥醇溶蛋白被分解成致敏多肽的機會增加，導致食用者產生麵筋不耐受反應。

溴酸鉀有致癌的可能，除美國外世界上的主要國家（中國，歐盟等）都禁用溴酸鉀作為膨發劑。這可能是杜編觀察到“許多麥麩（麵筋）不耐受的美國人到了歐洲吃小麥製品平安無事”的原因。

純屬臆測，供討論，非結論。

 對於想進一步了解麵包中的溴酸鉀的朋友，可參考：

Another Reason to Eat Organic – No Potassium Bromate in Your Bread

 

主要參考文章：

https://pubs.acs.org/doi/10.1021/jf070639n

J Agric Food Chem. 2007 Jun 27;55(13):5320-5. Epub 2007 May 31.

Impact of redox agents on the extractability of gluten proteins during bread making.

Lagrain B¹, Thewissen BG, Brijs K, Delcour JA.

Abstract

The gluten proteins gliadin and glutenin are important for dough and bread characteristics. In the present work, redox agents were used to impact gluten properties and to study gliadin-glutenin interactions in bread making. In control bread making, mixing increased the extractability of glutenin. The level of SDS-extractable glutenin decreased during fermentation and then further in the oven. The levels of extractable alpha- and gamma-gliadin also decreased during bread baking due to gliadin-glutenin polymerization. Neither oxidizing nor reducing agents had an impact on glutenin extractabilities after mixing. The redox additives did not affect omega-gliadin extractabilities during bread making due to their lack of cysteine residues. Potassium iodate (0.82-2.47 micromol/g of protein) and potassium bromate (1.07-3.17 micromol/g of protein) increased both alpha- and gamma-gliadin extractabilities during baking. Increasing concentrations of glutathione (1.15-3.45 micromol/g of protein) decreased levels of extractable alpha- and gamma-gliadins during baking. The work not only demonstrated that, during baking, glutenin and gliadin polymerize through heat-induced sulfhydryl-disulfide exchange reactions, but also demonstrated for the first time that oxidizing agents, besides their effect on dough rheology and hence bread volume, hinder gliadin-glutenin linking during baking, while glutathione increases the degree of covalent gliadin to glutenin linking.

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6617089/

Wheat proteins have been associated with a number of dietary disorders. The best well-known disorder is celiac disease, a disorder that develops in genetically susceptible individuals after ingesting gluten-containing cereals. Wheat gliadins, and to a lesser extent low molecular weight glutenins, carry immunogenic peptides [81]. A variety of these celiac-disease-initiating peptides of α-gliadin have been identified. Examples of some of these immunogenic epitopes are glia-α9 (PFPQPQLPY) and glia-α20 (FRPQQPUPQ) [82]. The unusual amino acid composition (high proline and glutamine contents) in gluten proteins prevents the complete digestion of these proteins in the gastrointestinal tract. While for most people the peptides do not cause any problems, an estimated 1% of the world population suffers from celiac disease [83] and in these individuals, these peptides trigger a cascade of auto-immune reactions that lead to severe intestinal damage. Several researchers have been trying to develop solutions for people suffering from celiac disease. One of these investigated solutions involves the pretreatment of the gluten protein with peptidase mixtures (e.g., papaya non-specific endopeptidase and three microbial peptidases (Aspergillus oryzae leucine aminopeptidase, Aspergillus melleus endopeptidase with activity against hydrophibic amino acid residues and Penicillium citrinum deutorlysin)) [84]. These peptidases are able to digest the above proline-rich peptides and, hence lower the concentration of the immunogenic peptides. Other strategies include the development of wheat varieties that do not trigger these gastrointestinal responses [81] and targeted processing of the cereals. One of such novel cereals is tritordeum, a hybrid of durum wheat and wild barley [85]. Tritordeum was shown to have lower numbers of immunogenic epitopes than regular wheat. This novel cereal is suitable to include in diets for people that want to reduce their gluten intake, but not for people suffering from celiac disease as there are still gluten immunogenic peptides produced upon digestion [85]. Processing has a big effect on the physicochemical properties of gluten, and will, hence, affect the digestive stability, and, hence, the antigenic potential of the protein [86]. Rahaman and colleagues [86] found that shear by itself does not affect protein digestibility, while pH and temperature substantially affect gluten digestibility and the antigenic characteristics of the hydrolysates that are formed. At pH 3, gluten undergoes acidic deamidation that will lead to a better hydrolysis of the proteins, generating smaller peptide fractions with a lower antigenicity [86,87]. When heating proteins, proteins are aggregating, increasing the resistance of the proteins against digestion [86]

 

https://zh.wikipedia.org/wiki/%E6%BA%B4%E9%85%B8%E9%92%BE

溴酸鉀[編輯]

維基百科，自由的百科全書

 

 

溴酸鉀
IUPAC名 Potassium bromate
別名	Potassium bromate(V) Bromic acid, potassium salt
識別
CAS號	7758-01-2
PubChem	23673461
ChemSpider	22852
SMILES	顯示▼ [K+].[O-]Br(=O)=O
InChI	顯示▼ 1/BrHO3.K/c2-1(3)4;/h(H,2,3,4);/q;+1/p-1
InChIKey	OCATYIAKPYKMPG-REWHXWOFAM
UN編號	1484
EINECS	231-829-8
ChEBI	38211
RTECS	EF8725000
KEGG	C19295
性質
化學式	KBrO3
摩爾質量	167.00 g/mol g·mol?¹
外觀	白色結晶粉末
密度	3.27 g/cm3
熔點	350 °C（623 K）
沸點	370 °C（643 K）
溶解性（水）	3.1 g/100 mL (0 °C) 6.91 g/100 mL (20 °C) 13.3 g/100 mL (40 °C) 49.7 g/100 mL (100 °C)
溶解性	微溶於乙醇 不溶於丙酮
結構
晶體結構	六邊形
熱力學
ΔfHmo298K	-342.5 kJ/mol
危險性
警示術語	R：R45 R9 R25
安全術語	S：S53 S45
歐盟分類	Carc. Cat. 2 Toxic (T) Oxidant (O)
NFPA 704	0 2 2
閃點	Non-flammable
致死量或濃度：
LD50（中位劑量）	157 mg/kg (oral, rat)[1]
若非注明，所有數據均出自一般條件（25 ℃，100 kPa）下。

溴酸鉀是一個無機鹽，室溫下為無色晶體，分子式為KBrO₃。

其在發酵、醒發及焙烤工藝過程中起到一種氧化劑的作用，使用了溴酸鉀後的麵粉更白，製作的麵包能快速膨脹，更具有彈性和韌性，在焙烤業被認為是最好的麵粉改良劑之一。溴酸鉀有致癌性，現在已被許多國家（如歐盟）禁用，但在美國仍允許使用。溴酸鉀在足夠長的烘烤時間和溫度下會耗盡，但是如果在麵粉中添加的太多就會有殘留。

中華人民共和國衛生部於2005年5月30日發布《2005年第9號公告》稱，根據溴酸鉀危險性評估結果，決定自2005年7月1日起，取消溴酸鉀作為麵粉處理劑在小麥粉中使用。在此之前按照《食品添加劑使用衛生標準》（GB2760-1996）使用溴酸鉀的食品可以在產品保質期內繼續銷售。