ABSTRACT
ABSTRACT This study describes the development of mixed flour added of maca for gluten-free bread (GFB) employing a Simplex Centroid Design. Four pseudo-components were evaluated in order to improve the GFB specific volume and texture profile analysis: maca (MC; 0.25 to 0.75), potato starch (PS; 0.25 to 0.75), sweet manioc flour (SEM; 0 to 0.25), and sour manioc flour (SOM; 0 to 0.25). The best GFB formulation - by desirability results - was evaluated regarding physio-chemical, microbiological aspects, and sensory acceptance. The responses specific volume and hardness were adjusted with a special cubic model (R2= 0.973 and 0.913), while cohesiveness, springiness and chewiness was adjusted with a linear model. The significant contribution of maca into GFB dough was evident in the models, and the desirability results indicated an appropriate mixed flour composed by MC (0.25), PS (0.5), and SEM (0.25). The GFB elaborated with this mixed flour generated a product well accepted (acceptability index higher than 73.9%) for attributes of aroma, colour, texture, flavour, and overall acceptance. The values of physio-chemical parameters obtained in the present article was in the range described for GFB in the literature. In addition, the processing method applied allowed for obtaining a GFB that was microbiologically stable.
RESUMEN Este estudio describe el desarrollo de la harina mezclada (MF) agregada de maca para la elaboración de pan sin gluten (GFB) empleando un Diseño Centroide Simplex. Se evaluaron cuatro pseudo-componentes para mejorar el volumen específico y el perfil de textura de GFB: maca (MC; 0,25 a 0,75), almidón de patata (PS; 0,25 a 0,75), harina de yuca dulce (SEM; 0 a 0,25), y harina de yuca agrio (SOM; 0 a 0,25). La mejor formulación de GFB - por la deseabilidad - se evaluó en relación con los aspectos fisicoquímicos, microbiológicos, y sensoriales. El volumen específico y la dureza se ajustaron a un modelo cúbico especial (R2= 0,975 y 0,913). La cohesión, elasticidad y masticabilidad se ajustaron a un modelo lineal. La contribución de la maca a la masa de GFB fue evidente en los modelos, y los resultados indican una MF apropiada compuesta por MC (0,25), PS (0.5) y SEM (0,25). El GFB elaborado con esta MF genera un producto aceptado (índice de aceptabilidad mayor que 73,9%) para aroma, color, textura, sabor y aceptación general. Los parámetros físico-químicos obtenidos estaban en el rango descrito para GFB en la literatura y GFB se mostró microbiológicamente estable.
Subject(s)
Bread/analysis , Celiac Disease , Lepidium , Diet, Gluten-Free , Taste , Solanum tuberosum , Bread/microbiology , ManihotABSTRACT
OBJECTIVE: The purpose of this study was to compare air trapping in healthy volunteers with asthmatics using pulmonary function test and quantitative data, such as specific volume change from paired inspiratory CT and registered expiratory CT. MATERIALS AND METHODS: Sixteen healthy volunteers and 9 asthmatics underwent paired inspiratory/expiratory CT. DeltaSV, which represents the ratio of air fraction released after exhalation, was measured with paired inspiratory and anatomically registered expiratory CT scans. Air trapping indexes, DeltaSV0.4 and DeltaSV0.5, were defined as volume fraction of lung below 0.4 and 0.5 DeltaSV, respectively. To assess the gravity effect of air-trapping, DeltaSV values of anterior and posterior lung at three different levels were measured and DeltaSV ratio of anterior lung to posterior lung was calculated. Color-coded DeltaSV map of the whole lung was generated and visually assessed. Mean DeltaSV, DeltaSV0.4, and DeltaSV0.5 were compared between healthy volunteers and asthmatics. In asthmatics, correlation between air trapping indexes and clinical parameters were assessed. RESULTS: Mean DeltaSV, DeltaSV0.4, and DeltaSV0.5 in asthmatics were significantly higher than those in healthy volunteer group (all p < 0.05). DeltaSV values in posterior lung in asthmatics were significantly higher than those in healthy volunteer group (p = 0.049). In asthmatics, air trapping indexes, such as DeltaSV0.5 and DeltaSV0.4, showed negative strong correlation with FEF25-75, FEV1, and FEV1/FVC. DeltaSV map of asthmatics showed abnormal geographic pattern in 5 patients (55.6%) and disappearance of anterior-posterior gradient in 3 patients (33.3%). CONCLUSION: Quantitative assessment of DeltaSV (the ratio of air fraction released after exhalation) shows the difference in extent of air trapping between health volunteers and asthmatics.
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Asthma/physiopathology , Exhalation/physiology , Healthy Volunteers , Lung/physiopathology , Respiratory Function Tests , Tomography, X-Ray Computed/methodsABSTRACT
The interaction of α-globulin with urea/guanidine hydrochloride was investigated by determining the apparent partial specific volumes of the protein in these solvents. The apparent partial specific volumes were determined both under isomolal and isopotential conditions. The preferential interaction parameter with solvent components calculated were 0.08 and 0.1 g of urea and guanidine hydrochloride respectively per g protein. In both the cases the interaction was not preferential with water. The total binding of denaturant to α-globulin was calculated both for urea and guanidine hydrochloride and the correlation between experimentally determined number of mol of denaturant bound per mol of protein and the total number of peptide bonds and aromatic amino acids were found to be in excellent agreement with each other. The changes in volume upon transferring α-globulin from a salt solution to 8 Μ urea and 6 Μ guanidine hydrochloride were also calculated.