Wheat flour sensitisation and airways disease in urban bakers.

A total of 176 bakers and 24 subjects employed as bread slicers and wrappers were studied to examine the effect of occupational category on respiratory symptoms, ventilatory capacity, non-specific bronchial reactivity, and prick skin test responses to wheat and common allergens. Bakers had a greater prevalence of attacks of wheeze and dyspnoea and more frequently considered that work affected their chests than did slicers and wrappers. Bakers with a history of asthma with onset since starting work in a bakery had a greater prevalence of chronic cough and sputum, increased bronchial reactivity, and positive prick skin test responses to wheat and common allergens than other bakers. There was a significant association between the frequency of positive prick skin tests to wheat and common allergens, suggesting that prior atopy facilitates sensitisation to cereal antigens. The frequency of positive prick skin responses to common allergens, however, declined with increasing baking duration whereas the frequency of positive skin responses to wheat increased with increasing baking duration, suggesting that subjects who were sensitised to common allergens were leaving the industry whereas subjects who stayed in the industry increased their risk of developing sensitisation to wheat. Oven handlers had a greater prevalence of attacks of wheeze and dyspnoea and more frequently considered that work affected their chests than either dough makers or general bakers. They also had a greater prevalence of positive prick skin test responses to wheat than dough makers or general bakers. Oven handlers also had a lower mean standardised casual FEV1 than either general bakers or dough makers. Thus oven handlers appear to have a greater risk of developing respiratory allergy and airflow obstruction than bakers in other occupational categories.     

Problems in diagnosing occupational allergy to flour: results of allergologic screening in apprentice bakers

Baker's respiratory allergy is reported as one of the most common forms of occupational allergy in many countries. At the first stage of a three-year study of risk factors of occupational allergy we investigated the symptoms reported, and the results of skin prick tests (SPT) to common and flour allergens in 461 current apprentice bakers from three different regions of Poland before starting occupational exposure. The occurrence of cough was reported by 14 subjects (3%), dyspnoea by 4 (0.87%), rhinitis by 18 (3.9%), conjunctivitis by 12 (2.6%) and skin symptoms by 12 subjects (2.6%). Generally, 48 subjects (10.41%) reported at least one symptom, which might suggest the existence of allergic disease. Positive SPT to at least one allergen was found in 99 subjects (21.5%), including 82 subjects (17.78%) with positive SPT to common allergens, 13 subjects (2.81%) to flour allergens and 4 subjects (0.88%) sensitised only to Dermatophagoides farinae. The statistical analysis revealed significant correlation between positive SPT to common allergens and reported rhinitis and conjunctivitis, and between positive SPT to occupational allergens and reported dyspnoea. Moreover, a significant correlation between positive SPT to D. pteronyssinus and D. farinae was found. In our opinion, the results of SPT should be very carefully examined, when diagnosing occupational allergy, as in some apprentice bakers positive results of SPT to flour allergens are found before vocational training. In all apprentice bakers, SPT to common and occupational allergens should be performed before starting occupational exposure. It would ensure the exclusion of subjects already sensitised to occupational allergens. Positive SPT to Dermatophagoides farinae has a very limited value in recognising baker's allergy.     

Bronchial hyperreactivity in potroom workers and prognosis after stopping exposure

A group of 30 potroom workers who developed an asthma-like syndrome during their work in the electrolytic extraction of aluminium (Alu-Swiss process with prebacked anodes) was followed up after stopping exposure. Subjective respiratory complaints were registered and a non-specific bronchial reactivity test using methacholine was performed once or twice during the follow up period (1984-9). After transfer to other work most workers either had an improvement in respiratory symptoms (60%) or even normalisation (27%); only 13% did not show changes. Bronchial hyperreactivity remained unchanged in 67% of workers, was less pronounced in 13%, normalised in 13%, and deteriorated in 7%. Smoking habits, atopy, and duration of exposure did not seem to have influenced the results obtained. No significant correlation was found between duration of exposure and the speed of onset of respiratory symptoms and the later prognosis of the syndrome. Based on the information collected during the period of observation it appears that reactive airway dysfunction syndrome, once induced, has a tendency to persist. An improvement in subjective complaints may be expected, however, after stopping exposure.     

Respiratory symptoms and wheat flour exposure: a study of flour millers

The objective of this study was to determine the prevalence of respiratory symptoms and their relationship to sensitization to wheat flour allergens and fungal amylase, in a group of workers from the UK flour milling industry. A cross-sectional study was used to evaluate symptoms, using a structured interview technique, and sensitization, using skin prick test findings, from 679 employees in flour milling and packing operations at 18 flour mills. A total of 147 workers (147/679, 22%) described upper respiratory tract symptoms of some kind. In the majority (139/147, 95%) these symptoms were of an occasional or transitory nature and were related to short-term exposures to high levels of dust. Three individuals (3/679, 0.4%) were identified whose symptoms were thought to be the result of allergy to wheat flour. The prevalence of positive skin prick tests to wheat flour allergens and to fungal amylase was 1.2% (8/678) and 0.9% (6/678), respectively. Measurements of total inhalable dust exposure for personnel exposed to flour dust were taken at 10 of the sites (116 samples). For production personnel the levels were typically between 1 and 10 mg/m3 (8-h time weighted average), with a median of 6.2 mg/m3. Hygiene operatives had appreciably higher exposure than production personnel, with a median of 18.7 mg/m3. Overall, 43% (50/116) of all samples exceeded 10 mg/m3 (8-h time weighted average). The findings suggest that the risk of sensitization to wheat flour allergens from current dust exposures in flour mills is very low. Wheat allergy was responsible in only a small proportion of the total who had respiratory symptoms. The principal causation of symptoms experienced by the workforce was considered to be a non-specific irritant effect related to short-term exposures to high levels of total inhalable dust.     

Follow-up of allergic symptoms in a group of health workers sensitized to latex

We studied 28 health care workers sensitised to latex and complaining of respiratory symptoms at work. All were females, aged 32 y (median), and had worked in the hospital for 12 y, in departments with high exposures (22 cases), moderate exposure (4 cases) or low exposure (2 cases) to rubber gloves. Twenty also complained of latex skin symptoms. Twenty-five (89%) were atopical (by prick test), and 16 (57%) had a personal history of allergic disease. Nine (32%) also had symptoms from exposure to latex outside work and 3 (10%) from food cross-reacting with latex. The specific inhalation test with latex gloves confirmed the diagnosis of asthma in 4 cases (14%) and of rhinitis in 13 cases (46%). We reinvestigated the workers 14 months (median) after the first examination to update exposure to latex, any allergic symptoms and adverse effects of relocation. At the follow-up, 3 workers (11%) had retired, all the others had stopped wearing powdered latex gloves, and 12 had changed their duties or the work-place. Ten (40%) of the 25 subjects still at work were without symptoms, 14 (56%) occasionally complained of mild symptoms and one of frequent rhinitis. Overall, we observed improvement of skin symptoms in 74% (14/19) of the cases and of respiratory symptoms in 56% (14/25) of the cases. Symptoms from exposure to latex outside work were still present in 6 subjects. The persistence of symptoms at work was significantly higher among workers who continued to work in departments with high/moderate latex glove exposure. The results of the study show that skin and respiratory symptoms among health care workers are related to the use of powdered latex gloves and confirm the importance of primary prevention.     

Bronchial hyperreactivity in potroom workers and prognosis after stopping exposure.

A group of 30 potroom workers who developed an asthma-like syndrome during their work in the electrolytic extraction of aluminium (Alu-Swiss process with prebacked anodes) was followed up after stopping exposure. Subjective respiratory complaints were registered and a non-specific bronchial reactivity test using methacholine was performed once or twice during the follow up period (1984-9). After transfer to other work most workers either had an improvement in respiratory symptoms (60%) or even normalisation (27%); only 13% did not show changes. Bronchial hyperreactivity remained unchanged in 67% of workers, was less pronounced in 13%, normalised in 13%, and deteriorated in 7%. Smoking habits, atopy, and duration of exposure did not seem to have influenced the results obtained. No significant correlation was found between duration of exposure and the speed of onset of respiratory symptoms and the later prognosis of the syndrome. Based on the information collected during the period of observation it appears that reactive airway dysfunction syndrome, once induced, has a tendency to persist. An improvement in subjective complaints may be expected, however, after stopping exposure.     

Effect of wheat flour, Bengal gram flour and corn flour on lipid metabolism in rats

Male albino rats were fed on respective diets of wheat flour, Bengal gram flour and corn flour for 8 weeks at the 59% level. It was observed that the increase in weight after wheat flour and Bengal gram flour feeding was 6.8 and 12.0% respectively and that the decrease after corn flour feeding was 5.2% as compared to the control animals on sucrose diet. Serum cholesterol and liver cholesterol levels were significantly (p less than 0.01) decreased after wheat flour, Bengal gram flour and corn flour feeding.     

Humoral immune responses of workers occupationally exposed to wheat flour

Wheat flour is a complex organic dust likely to induce immune responses when inhaled in work environment conditions. We compared the humoral status of 159 exposed workers from 11 flour mills and one industrial bakery with that of 41 workers from a salt factory. IgG, IgA, and IgM levels of antibodies to whole flour and to gliadin were assayed using ELISA tests in serum and saliva samples. Serum levels of IgG and IgA to both antigens were significantly higher (p < 0.0001) in occupationally exposed workers. Exposed workers had significantly higher levels of salivary IgG (p = 0.005) and IgA (p < 0.0001) to whole flour and of salivary IgG (p = 0.0005) to gliadin. In both groups, similar levels of anti-gliadin salivary IgA antibodies were observed. These data suggest that occupational exposure to wheat flour triggers specific immune responses, most likely through stimulation of the mucosal immune system. The presence of significant levels of serum antibodies, however, indicates that a systemic immunologic response is also present among exposed individuals.     

Alkylresorcinols in wheat and rye flour and bread

The alkylresorcinol (AR) content and relative homologue composition were determined in Norwegian flours and bread. The following average values for total AR content (μg/g dm) were found: wholegrain wheat flour available only to bakers (490) and to both consumers and bakers (710), refined wheat flour (36), wheat bran (3625), wholegrain spelt wheat flour (650), refined spelt wheat flour (80), wholegrain rye flour (972), refined rye flour (90) and rye bran (2753). The C17:0/C21:0 ratio was 0.1 for wheat and 0.8–0.9 for rye, confirming that it can be used to distinguish between wheat and rye. The AR content of Norwegian refined wheat flour was higher than that of Swedish, due to a consistently higher milling extraction rate in Norway. The content of AR varied from 27 to 2766 μg/g dm in hard bread and 21 to 548 μg/g dm in soft bread. The highest contents were found in bread with a high proportion of wholegrain flour and/or bran, in agreement with earlier studies. There was a good correlation (r = 0.91) and a high compliance between calculated and analysed AR levels in soft bread, confirming that AR can be used as a biomarker for wholegrain wheat and/or rye content in a cereal product.     

Wholewheat flour ensures higher mineral absorption and bioavailability than white wheat flour in rats

Consumption of unrefined whole flour is thought to affect mineral bioavailability because it contains high levels of fibre and phytic acid. The present experiment was designed to study the absorption of minerals from diets based on wholewheat flour and white wheat flour in rats. Two groups of male Wistar rats were fed on the diets for 3 weeks and absorption and tissue retention of minerals were studied. The rats fed on the wholewheat flour diet had significantly greater food intake, weight gain, faecal excretion and intestinal fermentation than those fed on the white flour diet. Mineral intakes, except for Ca, were significantly greater in rats fed on the wholewheat flour diet (4-fold for Mg, 2-fold for Fe and Zn). A significant rise in the apparent absorption of Fe (%) and a significant decrease in the apparent absorption of Zn (%) were observed. The amounts of minerals absorbed (mg/d) were significantly enhanced (excepted for Ca) with the wholewheat flour diet. Moreover, plasma and tibia levels of Mg and plasma, liver and tibia levels of Fe were significantly increased in rats fed on the wholewheat flour diet compared with those fed on the white flour diet. In conclusion, wholewheat flour, rich in phytic acid and minerals, did not have a negative effect on mineral absorption, but rather improved the bioavailability of some minerals. Human studies are needed to confirm these rat results before extrapolation to human nutrition.     

Use of sodium stearoyl lactylate and azodicarbonamide in wheat flour breads with added pea flour

Different amounts of sodium stearoyl lactylate (SSL) (X(1)) and azodicarbonamide (ADA) (X(2)) were analyzed to measure their effect on breadmaking using wheat flour with incorporation of pea flour (Pisum sativum) to the dough. The objective of the present work was to optimize the physical properties of dough (Y(1)Y(2)Y(3)Y(4)), the dough consistency during mixing (Y(5)Y(6)) and the baking performance (Y(7)Y(8)Y(9)). A central composite design and second-order models for Y(i) were employed. For dough physical properties and dough consistency during mixing, the best response was found when SSL varied between 0.5 and 1.5% and ADA between 110 and 170 ppm. For responses concerning the baking performance, better values for specific volume, crumb texture scores and bread score were obtained using SSL between 0.9 and 1.4% and ADA between 50 and 80 ppm. It is concluded that for baking with wheat flour replaced at about 10% with inactivated pea flour it should be advised to use SSL at levels close to 1% with ADA between 50 and 80 ppm.     

Use of sodium stearoyl lactylate and azodicarbonamide in wheat flour breads with added pea flour

Different amounts of sodium stearoyl lactylate (SSL) (X₁) and azodicarbonamide (ADA) (X₂) were analyzed to measure their effect on breadmaking using wheat flour with incorporation of pea flour (Pisum sativum) to the dough. The objective of the present work was to optimize the physical properties of dough (Y₁Y₂Y₃Y₄), the dough consistency during mixing (Y₅Y₆) and the baking performance (Y₇Y₈Y₉). A central composite design and second-order models for Y_i were employed. For dough physical properties and dough consistency during mixing, the best response was found when SSL varied between 0.5 and 1.5% and ADA between 110 and 170 ppm. For responses concerning the baking performance, better values for specific volume, crumb texture scores and bread score were obtained using SSL between 0.9 and 1.4% and ADA between 50 and 80 ppm. It is concluded that for baking with wheat flour replaced at about 10% with inactivated pea flour it should be advised to use SSL at levels close to 1% with ADA between 50 and 80 ppm.     

Flour,dough and bread properties of wheat flour substituted with orange-fleshed sweetpotato flour

This study investigated some quality attributes of composite flours, dough and bread from wheat flour substituted with orange-fleshed sweetpotato (OFSP) flour at 0–30% levels. Chemical, functional and pasting properties of flours, rheological properties of dough, as well as chemical composition and physical properties of bread were determined. Protein content of composite flours decreased by 25.51–37.37% at 10–30% OFSP flour substitution. Flour composites were higher in ash (2.12–2.33%), crude fibre (3.28–4.34%), water (1.45–2.08 ml/g) and oil (1.45–1.67 ml/g) absorption capacities. Wheat flour (100%) had maximum peak viscosity of 117.71 Rapid Visco Units (RVU) which decreased by 0.71–30.80% with OFSP flour substitution. Dough from composites had higher hydration (82.15–112.10%) and breakdown torque (0.38–0.42 Nm) but lower stability (1.16–2.38 min), protein weakening (0.06–0.37 Nm), starch gelatinization (0.46–0.81 Nm), stability of hot gel (0.04–0.43 Nm) and starch retrogradation (0.46–0.81 Nm). Bread substituted with OFSP flour had higher total carotenoids (1565.50–5179.27 µg/100 g), weight (193.74–198.50 g) and crumb moisture (27.81–27.91%).