Assessing the Sensitizing and Allergenic Potential of the Albumin and Globulin Fractions from Amaranth (Amaranthus hypochondriacus) Grains before and after an Extrusion Process.

Background: The first cases of food allergy to amaranth grain have recently been published. This pseudocereal is considered hypoallergenic, and there is scarce information about the allergenic potential of amaranth proteins, either before or after food processing. Objective: To evaluate, in a mouse model of food allergy, the sensitizing and allergenic potential of extruded and non-extruded albumin and globulin fractions from amaranth grains. Materials and Methods: Amaranth (Amaranthus hypochondriacus) flour was obtained and the albumin and globulin fractions isolated. These protein fractions were also obtained after flour extrusion. An intraperitoneal 28-day protocol was carried out to evaluate the sensitizing and allergenic potential of the proteins. The common and rarely allergenic proteins ovalbumin and potato acidic phosphatase were utilized as reference. Specific IgE and IgG antibodies were evaluated for all the proteins tested. Mast cell protease-1 (mMCP-1) responses were evaluated in serum samples collected after intragastric challenges with the proteins of interest. All serological evaluations were carried out using ELISA. Results: Mice were sensitized to the non-extruded albumin fraction from amaranth grains and to ovalbumin (p = 0.0045). The extrusion process of amaranth proteins abrogated the IgE responses triggered under non-extruded conditions (p = 0.0147). mMCP-1 responses were significantly detected in the group of mice sensitized to ovalbumin (p = 0.0138), but not in others. Conclusions: The non-extruded albumin fraction from amaranth has the potential to sensitize BALB/c mice, but this sensitizing potential fails to induce detectable serum levels of the mast cell degranulation marker mMCP-1 after intragastric challenges. Furthermore, the extrusion process abolished the sensitization potential of the amaranth albumins.

Amaranthus species around Bangkok, Thailand and the release of allergenic proteins from their pollens.

BACKGROUND: Pollen of Amaranthus L., commonly known as careless weed or Phak-khom in Thai, has become one of the major causes of airway allergy in many countries including Thailand. Despite its recognized importance, there is no available information about which Amaranthus species are producing allergenic pollen more likely to affect Thai patients. Furthermore, only allergenic proteins released from pollen can cause allergy. OBJECTIVE: This study aimed to survey species of Amaranthus found in Bangkok and to investigate the impact of water on pollen damage and protein release from Amaranthus pollens. METHODS: Amaranthus inflorescences were sampled and identified using the identification key provided in "Flora of Thailand". Shed pollens were collected on day 1, 3 and 7 after shedding. Ten mg of pollens in distilled water including damaged pollens were counted under a light microscope. In addition, supernatant was analyzed for concentration of proteins released from pollens using Bradford's assay. Profiles of released proteins and IgE binding proteins were analyzed by SDS-PAGE and Western blot. RESULTS: Three species of Amaranthus-A. hybridus, A. spinosus, and A. viridis were identified. SDS-PAGE analysis revealed at least twelve protein bands with MW ranging from 10 to 80 kDa. Water caused more damage to pollens and higher amount of proteins were recovered from pollens 1 day after shedding than from 3- and 7-days old pollens. The results of Western blot showed IgE-bound proteins with MW ranging from 30 to 50 kDa. CONCLUSIONS: Water could damage pollens and time after shedding and significantly affected the amount of allergenic proteins released from pollen.

First case report of anaphylaxis caused by Rajgira seed flour (Amaranthus paniculatus) from India: a clinico-immunologic evaluation.

The prevalence of food allergy is reported to be 3-4% in adults and about 6% in children. However food allergy across different countries accounts for 35-50 % all cases of anaphylaxis to foods. In the present study, we have reported a case of anaphylaxis to Amaranth grain (Amaranthus paniculatus) commonly known as Rajgira (Ramdana) in India. A 60 year old female suffered anaphylaxis after consuming Rajgira seed flour generally consumed during fasting. Food allergy to Amaranth seeds is not reported so far. The patient reported to hospital with complaints of itching in mouth, choking throat, redness and swelling of face and burning abdomen within 5 min of consuming Rajgira flour. Clinical and immunological investigations revealed SPT and oral challenge positivity beside high allergen specific IgE in the serum of the patient. Three IgE binding protein fractions were detected in roasted Rajgira seed flour extract which could be considered to be allergenically important for triggering anaphylaxis.

Dietary intake of cadmium from Bangladeshi foods.

UNLABELLED: Human exposure to cadmium (Cd) is associated with various diseases and high levels of Cd have been detected in Bangladeshi population warranting further research to identify the source of this exposure. In this study, Cd levels in 327 and 94 samples of Bangladeshi food and non-food samples, respectively, were determined using inductively coupled plasma mass spectrometry. This is the largest number of Bangladeshi food and nonfood samples investigated for their Cd content. High Cd levels were detected in leafy vegetables (mean 31 [SD 29]µg/kg). Of these vegetables, lal shak (Amaranthus tricolor) contained the highest Cd level (303 µg/kg [wet weight]; mean 100.5 [SD 95]µg/kg). Bangladeshi rice also showed significant concentration of Cd (mean 37.2 [SD 30]µg/kg). Of particular concern is the very high level of Cd detected in some puffed rice, which we attribute to the illegal practice of using urea for whitening the puffed rice. Tobacco leaves, which are commonly consumed during betel quid chewing by Bangladeshis, contain significant levels of Cd (mean 95 [SD 87]µg/kg). The total daily intake (TDI) of Cd from foods for Bangladeshis was estimated to be 34.55 µg/d. This is rather high when compared to the TDI of Cd for other populations. Our analysis reveals that this is mainly due to the very high intake of rice and vegetables, and lower consumption of animal products (which are low in Cd), by the Bangladeshis. We also determined the provisional maximum tolerable daily intake and target hazard quotients values for Cd. Clearly a more balanced diet is necessary to reduce the Cd intake in the Bangladeshi population, especially by reducing the very high intake of rice and certain leafy vegetables. Food manufacturing and agricultural practices needs to be altered to reduce the entry of Cd into the food chain. PRACTICAL APPLICATION: Exposure to high levels of Cd can be harmful to human health and this study provides a comprehensive analysis of Cd levels in a variety of food items from Bangladesh. The findings are of particular importance to consumers of Bangladeshi foods in both Bangladesh and in other countries. Data obtained will be valuable resources for food safety and regulatory bodies as our study suggests entry of Cd in foods through use of illegal chemicals in food manufacturing processes.

Efeito do processamento na atividade antioxidante do grão de amaranto (Amaranthus cruentus L. BRS-Alegria) / Effect of processing on the antioxidant activity of amaranth grain

As características nutricionais, funcionais e agrícolas do amaranto são responsáveis pelo aumento do interesse por este alimento nas últimas décadas. O grão pode ser cozido, estourado, torrado, extrusado ou moído para ser consumido. Foi avaliado o efeito destes processamentos na atividade antioxidante do grão de amaranto, através das determinações do teor de fenólicos totais e da atividade antioxidante in vitro por dois métodos: inibição da oxidação lipídica pelo sistema β-caroteno/ácido linoléico e índice de atividade antioxidante pelo aparelho Rancimat®. Os processamentos reduziram em média o teor de fenólicos totais do grão de amaranto de 31,7 para 22,0 mg de equivalentes de ácido gálico/g de resíduo seco. Observou-se que o extrato obtido por etanol do grão torrado foi o único a apresentar menor índice de atividade antioxidante (IAA) em relação ao grão cru (1,3 v 1,7). Os processos de extrusão, torração e explosão não alteraram a capacidade de inibição da oxidação lipídica (IOL) do amaranto (55 por cento). Já o cozimento aumentou o IOL (79 por cento), o que pode ter ocorrido devido ao maior tempo de processamento sob alta temperatura (100ºC/10min). Os métodos mais comuns de processamento do grão de amaranto ocasionaram redução do teor de fenólicos totais, no entanto a atividade antioxidante do estourado e do extrusado, avaliada pelos dois métodos, foi semelhante ao do grão cru. O grão de amaranto tanto cru como processado apresenta potencial antioxidante. Polifenóis, antocianinas, flavonóides, tocoferóis, vitamina C e compostos gerados na reação de Maillard podem estar relacionados à atividade antioxidante deste grão.

Amaranth has attracted increasing interest over recent decades because of its nutritional, functional and agricultural characteristics. Amaranth grain can be cooked, popped, toasted, extruded or milled for consumption. This study investigated the effect of these processes on the antioxidant activity of amaranth grain. Total phenolic content and in vitro antioxidant activity were determined according to two methods: inhibition of lipid oxidation using the β-carotene/linoleic acid system and the antioxidant activity index using the Rancimat® apparatus. The processing reduced the mean total phenolics content in amaranth grain from 31.7 to 22.0 mg of gallic acid equivalent/g of dry residue. It was observed that the ethanol extract from toasted grain was the only one that presented a lower antioxidant activity index compared with the raw grain (1.3 versus 1.7). The extrusion, toasting and popping processes did not change the capacity to inhibit amaranth lipid oxidation (55 percent). However, cooking increased the inhibition of lipid oxidation (79 percent), perhaps because of the longer time at high temperatures in this process (100°C/10 min). The most common methods for processing amaranth grain caused reductions in the total phenolics content, although the antioxidant activity of popped and extruded grain, evaluated by the two methods, was similar to that of the raw grain. Both raw and processed amaranth grain presents antioxidant potential. Polyphenols, anthocyanins, flavonoids, tocopherols, vitamin C levels and Maillard reaction products may be related to the antioxidant activity of this grain.

Dynamic changes in sensitization to specific aeroallergens in children raised in a desert environment.

BACKGROUND: Allergen skin test reactivity and total serum IgE are objective measures used to characterize and help diagnose allergic diseases. Cross-sectional studies have shown that overall aeroallergen skin test reactivity increases throughout childhood. However, little attention has been paid to whether individual aeroallergen remittance occurs, which could distort or mask relationships to disease. OBJECTIVE: To access the incidence and remittance of skin test reactions to individual allergens in children aged 6-11 years. METHODS: Longitudinal sensitization to six aeroallergens and total IgE were assessed in 828 children raised in the semi-arid US southwest at ages 6 and 11 years. RESULTS: New sensitization (to any allergen) between 6 and 11 years occurred in 30.2% of children compared with 39.7% before age 6 years. The rate of complete remittance from positive to negative between ages 6 and 11 years was 8.2%, and total IgE at age 6 years was not predictive. Remittance rates for individual allergens were high and variable (19-49%). The perennial allergens Bermuda and Alternaria were early sensitizers and had low remittance rates. Early sensitization to the four seasonal allergens was less common and more subject to remittance with the bulk of sensitization occurring between 6 and 11 years. CONCLUSION: This study shows that sensitization to individual aeroallergens in childhood is dynamic and indicates the limitation of single point assessment of skin test reactivity.