Many persons worldwide are deficient in micronutrients, two of the most common being vitamin A and iron. Fortification of staple food is a commonly used and effective method of boosting micronutrient intake. Wheat flo...Many persons worldwide are deficient in micronutrients, two of the most common being vitamin A and iron. Fortification of staple food is a commonly used and effective method of boosting micronutrient intake. Wheat flour is widely used around the world and makes a good vehicle for fortification, but there is a lack of studies on the storage stability of fortified wheat flour. In this study, we fortified wheat flour with elevated levels of vitamin A and three sources of iron and stored it for up to 16 weeks at refrigerated or room temperature or elevated temperature. The rate of disappearance of vitamin A was monitored by high pressure liquid chromatography, and the rate of disappearance was fotmd to be directly proportional to the duration of storage and storage temperature. Higher temperatures contributed to greater loss of vitamin A. Iron, regardless of source, did not play a major role in contributing to the rate of vitamin A loss. Flour functionality was assessed by baking loaves of bread from the stored flour and assessing physical properties as well as subjecting the loaves to an expert sensory panel. Functionality also changed with time and temperature of storage, but sensory analysis found that these changes were not detrimental to the quality of bread baked from the stored flours. Trained sensory panelists found that breads baked from flours fortified with ferrous sulfate and stored at the three temperatures for times up to eight weeks were markedly different from fortified flours using hydrogen reduced irons.展开更多
To reveal the effects of Fe2＋ on bacterial communities in the early stages of minerals dissolution, two different acid mine drainage （AMD） samples were collected at Dabaoshan Mine and Shenbu Mine. Community success...To reveal the effects of Fe2＋ on bacterial communities in the early stages of minerals dissolution, two different acid mine drainage （AMD） samples were collected at Dabaoshan Mine and Shenbu Mine. Community successions of AMD niches were analyzed by Amplified Ribosomal DNA Restriction Analysis （ARDRA）, sequencing, and phylogenetic analysis in original AMD samples and their subculture under Fe2＋ concentrations. Although geochemical properties and community structures were greatly different between the two original AMD samples, bacterial community successions were still very similar under high Fe2＋ concentrations. The results showed that Acidithiobacillus ferrooxidans have competitive relationship with other bacterial species living in the AMD, including species that were also capable of oxidizing ferrous ion. A competitive relationship among different At. ferrooxidans strains likewise existed. Some of At. ferrooxidans can grow first under conditions of high ferrous ion concentration, and other At. ferrooxidans species decreased gradually and disappeared. This suggested that these species of At. ferrooxidans are most acidophilic bacteria and afford Fe3＋ to leach other metallic ion in the early stages of minerals dissolution.展开更多
文摘Many persons worldwide are deficient in micronutrients, two of the most common being vitamin A and iron. Fortification of staple food is a commonly used and effective method of boosting micronutrient intake. Wheat flour is widely used around the world and makes a good vehicle for fortification, but there is a lack of studies on the storage stability of fortified wheat flour. In this study, we fortified wheat flour with elevated levels of vitamin A and three sources of iron and stored it for up to 16 weeks at refrigerated or room temperature or elevated temperature. The rate of disappearance of vitamin A was monitored by high pressure liquid chromatography, and the rate of disappearance was fotmd to be directly proportional to the duration of storage and storage temperature. Higher temperatures contributed to greater loss of vitamin A. Iron, regardless of source, did not play a major role in contributing to the rate of vitamin A loss. Flour functionality was assessed by baking loaves of bread from the stored flour and assessing physical properties as well as subjecting the loaves to an expert sensory panel. Functionality also changed with time and temperature of storage, but sensory analysis found that these changes were not detrimental to the quality of bread baked from the stored flours. Trained sensory panelists found that breads baked from flours fortified with ferrous sulfate and stored at the three temperatures for times up to eight weeks were markedly different from fortified flours using hydrogen reduced irons.
文摘To reveal the effects of Fe2＋ on bacterial communities in the early stages of minerals dissolution, two different acid mine drainage （AMD） samples were collected at Dabaoshan Mine and Shenbu Mine. Community successions of AMD niches were analyzed by Amplified Ribosomal DNA Restriction Analysis （ARDRA）, sequencing, and phylogenetic analysis in original AMD samples and their subculture under Fe2＋ concentrations. Although geochemical properties and community structures were greatly different between the two original AMD samples, bacterial community successions were still very similar under high Fe2＋ concentrations. The results showed that Acidithiobacillus ferrooxidans have competitive relationship with other bacterial species living in the AMD, including species that were also capable of oxidizing ferrous ion. A competitive relationship among different At. ferrooxidans strains likewise existed. Some of At. ferrooxidans can grow first under conditions of high ferrous ion concentration, and other At. ferrooxidans species decreased gradually and disappeared. This suggested that these species of At. ferrooxidans are most acidophilic bacteria and afford Fe3＋ to leach other metallic ion in the early stages of minerals dissolution.
