Maize food allergy: a double‐blind placebo‐controlled study

Background Maize allergy is not very common especially in Europe. The number of studies that address IgE mediated maize allergy is all too few. Objective Evaluate subjects with a history of maize allergy by double‐blind, placebo‐controlled food challenge; identify the spectrum of symptoms manifested during challenge; determine the lowest provocation dose (PD) during challenge; determine the performance characteristics of maize skin prick test and specific IgE. Methods Twenty‐seven patients with a history of maize allergy were enrolled to be evaluated by skin test, specific IgE and double‐blind placebo‐controlled maize challenge. Results Forty‐eight percent of the patients were challenge positive. PD range was 0.1–25 g. Fifty‐four percent of the maize allergic subjects had a PD that was 2.5 g; two subjects reacted to 100 mg of maize. Comparison of maize specific IgE levels and skin test results to the challenge results revealed the following (specific IgE level/skin testing): sensitivity 1.00/0.846, specificity 0.077/0.384, positive predictive value 0.520/0.579, and negative predictive value 1.00/0.714. Conclusion Maize is a cause of IgE‐mediated allergic reactions to foods in adults and children. Nearly half of the subjects recruited were confirmed by challenge to be allergic to maize. Twenty‐three percent of the positive challenge patients manifested symptoms that involved two organ systems, thus fulfilling the criteria for maize induced anaphylaxis. Maize is allergenic and can pose a risk for symptomatic food allergy at a dose of 100 mg.     

Opaque-2 maize in the prevention and treatment of pellagra

In order to determine the usefulness of opaque-2 maize in the prevention of pellagra, people from the third and fifth brigades of a commune in a maize-eating district of Northwest China received opaque-2 maize in their diet and served as the experimental subjects. People from the neighboring sixth brigade ate conventional maize and served as the control subjects. After three months there were no cases of pellagra in the experimental groups, but there were three cases in the control group; the incidence was 1.8%.Prior to the study, urinary excretion values of N-methylniacinamide (N-MN) of the subjects were measured. There were no significant differences among the three brigades (P>0.05). By the conclusion of the study the differences in urinary excretion of N-MN between the experimental and control groups were highly significant: 0.21±0.02 and 0.21±0.02 mg/2 h for the experimental groups and 0.12±0.01 mg/2 h for the control group.Opaque-2 maize also was used in a study of the treatment of pellagra. Persons with pellagra were divided into three groups: Group 1 received opaque-2 maize, Group 2 received conventional maize plus niacinamide (10 mg per day), and Group 3 received conventional maize. Before treatment, the average values of the urinary excretion of N-MN of each group were not significantly different. After one month of the treatment, a loading dose of 50 mg niacinamide was administered orally. Four-hour urines were collected and analyzed for N-MN. The differences between Group 1 and Group 3 or Group 2 and Group 3 were significant. Although the results showed that opaque-2 maize could be used in the prevention and treatment of pellagra, meat, milk, and milk products should be recommended to people in all of the areas where pellagra is endemic. The planting of opaque-2 maize, however, should provide an effective means to supply utilizable niacin and is a simple, economical way to prevent pellagra for the present.     

Occurrence of Mycotoxins and Toxigenic Fungi in Cereals and Application of Yeast Volatiles for Their Biological Control

Fungal infections in cereals lead to huge economic losses in the food and agriculture industries. This study was designed to investigate the occurrence of toxigenic fungi and their mycotoxins in marketed cereals and explore the effect of the antagonistic yeast Cyberlindnera jadinii volatiles against key toxigenic fungal strains. Aspergillus spp. were the most frequent contaminating fungi in the cereals, with an isolation frequency (Fr) of 100% in maize, followed by wheat (88.23%), rice (78.57%) and oats (14.28%). Morphological and molecular identification confirmed the presence of key toxigenic fungal strains in cereal samples, including A. carbonarius, A. flavus, A. niger, A. ochraceus and A. parasiticus. Aflatoxins (AFs) were detected in all types of tested cereal samples, with a significantly higher level in maize compared to wheat, rice, oats and breakfast cereals. Ochratoxin A (OTA) was only detected in wheat, rice and maize samples. Levels of mycotoxins in cereals were within EU permissible limits. The volatiles of Cyberlindnera jadinii significantly inhibited the growth of A. parasiticus, A. niger and P. verrucosum. The findings of this study confirm the presence of toxigenic fungi and mycotoxins in cereals within the EU permissible limits and the significant biocontrol ability of Cyberlindnera jadinii against these toxigenic fungi.     

Endophytic colonization of entomopathogenic fungi increases plant disease resistance by changing the endophytic bacterial community

Various mechanisms are involved in plant disease resistance mediated by entomopathogenic fungi; however, the role of plant endophytic microbes in disease resistance is unknown. In the present study, we showed that the disease incidence of northern corn leaf blight caused by Exserohilum turcicum (Et) on maize was reduced significantly by soil inoculation with Beauveria bassiana (Bb). Meanwhile, B. bassiana colonization and E. turcicum infection increased the diversity and abundance and diversity of endophytic bacteria and fungi, respectively, while the abundance of endophytic bacterial of the Bb + Et treatment decreased significantly compared with that of Et treatment alone. However, Bb + Et treatment increased the relative abundance of plant beneficial bacteria significantly, for example, Burkholderia and Pseudomonas. Network analyses showed that the microbiome complexity increased after soil inoculation with B. bassiana. Taken together, these results revealed the potential mechanism by which entomopathogenic fungi exert biological control of maize leaf spot disease.     

Sequence composition and genome organization of maize

Zea mays L. ssp. mays, or corn, one of the most important crops and a model for plant genetics, has a genome approximately 80% the size of the human genome. To gain global insight into the organization of its genome, we have sequenced the ends of large insert clones, yielding a cumulative length of one-eighth of the genome with a DNA sequence read every 6.2 kb, thereby describing a large percentage of the genes and transposable elements of maize in an unbiased approach. Based on the accumulative 307 Mb of sequence, repeat sequences occupy 58% and genic regions occupy 7.5%. A conservative estimate predicts approximately 59,000 genes, which is higher than in any other organism sequenced so far. Because the sequences are derived from bacterial artificial chromosome clones, which are ordered in overlapping bins, tagged genes are also ordered along continuous chromosomal segments. Based on this positional information, roughly one-third of the genes appear to consist of tandemly arrayed gene families. Although the ancestor of maize arose by tetraploidization, fewer than half of the genes appear to be present in two orthologous copies, indicating that the maize genome has undergone significant gene loss since the duplication event.     

Changing food habits in Africa

In planning for the improvement of Nutrition in Africa there is a need to change food habits. This paper reports on studies of food taboos and food habits in Nigeria and discusses their implication in the present‐day eating habits of the people. The great interest of Africans in education will play a great part in helping to change food habits and a plea is made for much more use of formal and informal education for changing food habits on the continent. The paper also discusses the factors that come into play in informal changes of food habits and discusses ways in which these could be used to improve the diet in Africa.     

牧草青贮质量评定和青贮潜在问题

青贮可以潜在降低牧草收获和储存养分的损失,是奶牛场最常用的饲料。青贮是一种潜在的动态饲料,如果增加氧气可以导致青贮质量最坏。本目标评估青贮饲料质量和饲养管理,以确定在奶牛场的生产或健康问题潜在的作用。     

Sweetpotato-based complementary food would be less inhibitory on mineral absorption than a maize-based infant food assessed by compositional analysis

The availability of micronutrients from sweetpotato-based complementary foods (CFs): oven-toasted and roller-dried ComFa, and from a maize-based infant food, enriched Weanimix, was compared using phytate/mineral molar ratios, polyphenols and β-carotene levels. The phytate/calcium, iron and zinc molar ratios of approximately 0.17, 1 and 15 predict better absorption of calcium, iron and zinc respectively. Generally, the sweetpotato-based CFs had at least half the phytate/mineral ratios of enriched Weanimix. The phytate/iron ratio in both the sweetpotato- and the maize-based CFs was greater than 1. Only the ComFa formulations had phytate/zinc ratio lower than 15. The level of polyphenol (iron inhibitor) was similar for the formulations. Only the sweetpotato-based CFs contained measurable levels of β-carotene, a possible iron enhancer. The lower phytate/mineral ratios and the β-carotene level of the sweetpotato-based CFs suggest that calcium, iron and zinc absorption could be better from them than from the maize-based infant food.