The rehydration attributes and quality characteristics of 'Quick-cooking' dehydrated beans: Implications of glass transition on storage stability.

Storage stability is an essential consideration for minimizing the deteriorative quality changes in foods post-processing. This study, for the first, time aimed to gain insight into the storage stability of quick-cooking 'convenient' dehydrated beans (Phaseolus vulgaris L.) using the glass transition (Tg) concept. Quick-cooking dehydrated beans were prepared by hydrothermal treatment of fresh beans followed by air-drying and are rehydrated prior to use. The impact of storage temperatures (25, 28, 35 and 42 °C) on the rehydration indices (rate constant and extent) and quality characteristics (colour, texture and volatile profile) of the beans were studied. The results indicate a decrease in the rehydration rate constants with increasing storage temperatures and duration. The rehydration ability also significantly decreased with increased storage duration (>28 °C) suggesting a strong inverse link with hardness. Although there was no overall colour change with storage, the formation of new volatiles associated with non-enzymatic chemical reactions occurred at elevated temperatures (28-42 °C). Identification of the critical water contents based on the Tg-moisture relation and the moisture sorption isotherm revealed that dehydrated beans of 10 % moisture content stored below 28 °C are in a glassy state. Overall, the quality characteristics are significantly influenced by storage and the utilization of the glass transition concept allows for identifying suitable storage conditions.

The Impact of Drying and Rehydration on the Structural Properties and Quality Attributes of Pre-Cooked Dried Beans.

Fresh common beans can be made 'instant' to produce fast-cooking beans by first soaking and cooking the beans before drying to create a shelf-stable product that can be rehydrated at the time of use. This study investigated the interplay between the drying process (air, vacuum and freeze drying), the microstructure and functional attributes of rehydrated pre-cooked beans. The microscopic study revealed that the three different drying techniques resulted in distinctly different microstructures, with the freeze drying process resulting in highly porous materials, while the air- and vacuum-dried samples underwent shrinkage. Additionally, the rehydration behavior (modeled using empirical and diffusion models) demonstrates that the high rehydration rate of freeze-dried beans is due to capillarity, while rehydration, in the case of air- and vacuum-dried beans, is primarily diffusion-controlled. Irrespective of the drying technique, the high rehydration capacity supports little to no structural collapse or damage to the cell walls. The color and texture of the rehydrated beans did not differ greatly from those of freshly cooked beans. The total peak area of the volatiles of rehydrated beans was significantly reduced by the drying process, but volatiles characteristic of the cooked bean aroma were retained. This new understanding is beneficial in tailoring the functional properties of pre-cooked dry convenient beans requiring short preparation times.

The influence of upper respiratory tract infection to effusive otitis media

Study performed with 1168 children aged 1-15 in some kindergarten and maternal school, primary school and secondary school in the commune Trung Tu, Kim Lien – District Dong Da – Ha Noi had showed that 8,9% children had effusive otitis media. In the group of children with VA, the incidence of effusive otitis media was higher than in the group without VA (13,74% vs 8,01%). In the group of children with tonsilitis, the incidence of effusive otitis media was higher than in the group without tonsilitis (15,69% vs 8,26%)

Epidemiologic characteristics of catarrhal media otitis in children of preschool age in some kindergarten in Ha Noi

Study was carried out at some kindergarten with 773 children of 1-5 years old of age. Results showed an incidence of catarrhal media otitis of 10.34%. This incidence trends to increased in the lower age with a peak of 12.21% at the age of 2, then diminished gradually. The gender rate is 53.75% in boys comparing with 46.25% in girls. In 75.60% patients the condition occurred in both sides of two ears and in the case of unilateral development, the rate is 70.27% in the left in comparing with 29.73% in right ear

The relation between secretory otitis media and breast feeding

Among 773 children are diverse kindergartens and maternal school in Hanoi the prevalence of secretory otitis media, in winter is 18.49%, summer 11.25%, chronical – in both winter and summer 10.34%, in boys 53.75%, higher than girls 6.25%. The prevalence in breastfeeding infants lower significantly than in bottle feeding ones (9.78% versus 21.62%)

The relation between smoke and catarrhal otitis media

The influence of smoke on otitis media was investigated on 1168 children from 1 to 15 years old of age in Trung Tu and Kim Lien Quarters (Ha Noi) from July 2000 to 2001. The interview was performed on their parents with a questionary of 19 issues concerning the risk factor of otitis media, the examination of ENT and the measuring of ear volume were exerted by two times in all subjects during the period of 1 year. Results showed a prevalence of 8,9% of otitis media in Ha Noi children, the rate of boys is higher than that of girls. Smoke and environment pollution is one of the risk factors of high pulmonary tract infection and of catarrhal otitis media