Ultrastructural Studies of Raw and Processed Tissue of the Major Cultivated Mushroom, Agaricus bisporus

Commercial mushroom processors currently lose approximately 30 percent of the mushroom weight due to shrinkage during processing (blanching and canning) , resulting in substantial economic losses . Microscopy was used to assess the extent and type of chemical and structural changes induced by processing mushrooms and causing shrinkage. Scanning electron microscopy revealed that the processing operations including vacuum hydration , blanching , and thermal treatment do not damage the integrity of the tissue. Light microscopy revealed that the morphology of the tissue, shape and spacing of cells, appear similar for raw and processed mushroom tissue . However, the intra ce ll ular material remained indistinct for both tissue types, and the processed tissue appeared distorted. Transmission electron microscopy revealed that commercial mushroom processing caused intracellular damage to the tissue. The heat treatment caused the coagulation of cytoplasmic material and the disruption of intracellular membranes, resulting in the loss of water holding capacity of the tissue. Therefore, shrinkage of processed mushrooms results from denaturation of the organelles and the associated loss of water holding capacity by those organelles

Protein Hydrolysates Are Avoided by Herbivores but Not by Omnivores in Two-Choice Preference Tests

Background: The negative sensory properties of casein hydrolysates (HC) often limit their usage in products intended for human consumption, despite HC being nutritious and having many functional benefits. Recent, but taxonomically limited, evidence suggests that other animals also avoid consuming HC when alternatives exist. Methodology/Principal Findings: We evaluated ingestive responses of five herbivorous species (guinea pig, mountain beaver, gopher, vole, and rabbit) and five omnivorous species (rat, coyote, house mouse, white-footed mouse, and deer mouse; N = 16–18/species) using solid foods containing 20% HC in a series of two-choice preference tests that used a nonprotein, cellulose-based alternative. Individuals were also tested with collagen hydrolysate (gelatin; GE) to determine whether it would induce similar ingestive responses to those induced by HC. Despite HC and GE having very different nutritional and sensory qualities, both hydrolysates produced similar preference score patterns. We found that the herbivores generally avoided the hydrolysates while the omnivores consumed them at similar levels to the cellulose diet or, more rarely, preferred them (HC by the white-footed mouse; GE by the rat). Follow-up preference tests pairing HC and the nutritionally equivalent intact casein (C) were performed on the three mouse species and the guinea pigs. For the mice, mean HC preference scores were lower in the HC v C compared to the HC v Cel tests, indicating that HC’s sensory qualities negatively affected its consumption. However, responses were species-specific. For the guinea pigs, repeated exposure to HC or C (4.7-h sessions; N = 10) were found to increase subsequent HC preference scores in an HC v C preference test, which was interpreted in the light of conservative foraging strategies thought to typify herbivores. Conclusions/Significance: This is the first empirical study of dietary niche-related taxonomic differences in ingestive responses to protein hydrolysates using multiple species under comparable conditions. Our results provide a basis for future work in sensory, physiological, and behavioral mechanisms of hydrolysate avoidance and on the potential use of hydrolysates for pest management

Embryonal rhabdomyosarcoma of the chest wall: A case report and review of the literature

Embryonal rhabdomyosarcoma is a soft-tissue sarcoma which has a predilection for the head and neck area, genitourinary tract and the extremities. We report a rare case of embryonal rhabdomyosarcoma of the chest wall in an 8-year-old girl, presenting as a destructive tumor in the rib and clinically and radiologically mimicking Ewing′s sarcoma. Histopathological examination showed a small round cell tumor. Immunohistochemically, the positivity for muscle markers desmin and myogenin in the tumor cells proved to be useful for making a definitive diagnosis of embryonal rhabdomyosarcoma. Cytogenetic analysis revealed a high level of aneuploidy in the tumor cells, with double-minutes and additional chromosomal structural aberrations. The patient is responding well to chemotherapy

Analysis of physical parameters and determination of inflection point for Flattening Filter Free beams in medical linear accelerator

BackgroundMedical Linear accelerators manufactured without flattening filters are increasing popular in recent days. The removal of flattening filter results in increased dose rate, reduced mean energy, reduction in head leakage and lateral scattering, which have shown advantageous when used for special treatment procedures.AimThis study aims to analyze physical parameters of FFF beams and to determine the inflection point for standardizing the beam flatness and penumbra.Materials and methodsThe beam profiles and depth dose patterns were measured using Radiation Field Analyzer (RFA) with 0.13[[ce:hsp sp="0.25"/]]cc cylindrical ion chamber. The beam energy characteristics, head scatter factor (Sc) were obtained for 6FFF and 10FFF beams and compared with 6[[ce:hsp sp="0.25"/]]MV and 10[[ce:hsp sp="0.25"/]]MV photons, respectively. The symmetry and stability of unflattened regions were also analyzed. In addition, the study proposes a simple physical concept for obtaining inflection point for FFF beams and results were compared using the Akima spline interpolation method. The inflection point was used to determine the field size and penumbra of FFF beams.ResultsThe Sc varied from 0.922 to 1.044 for 6FFF and from 0.913 to 1.044 for 10FFF with field sizes from 3[[ce:hsp sp="0.25"/]]cm[[ce:hsp sp="0.25"/]]×[[ce:hsp sp="0.25"/]]3[[ce:hsp sp="0.25"/]]cm to 40[[ce:hsp sp="0.25"/]]cm[[ce:hsp sp="0.25"/]]×[[ce:hsp sp="0.25"/]]40[[ce:hsp sp="0.25"/]]cm which is much less than FF beams. The obtained value of field size and penumbra for both simple physical concept and Akima spline interpolation methods is within the ±1.0[[ce:hsp sp="0.25"/]]mm for the field size and ±2[[ce:hsp sp="0.25"/]]mm penumbra. The results indicate that FFF beams reduce Sc compared with FF beams due to the absence of a flattening filter.ConclusionThe proposed simple method to find field size and penumbra using inflection point can be accepted as it is closely approximated to mathematical results. Stability of these parameters was ascertained by repeated measurements and the study indicates good stability for FFF beam similar to that of FF beams

Studies on Whey Protein Concentrates. 1. Compositional and Thermal Properties

Cheddar-cheese-type whey protein concentrates were studied for their compositional and thermal attributes. The samples were prepared from three milk systems, namely, skim milk, whole milk, and skim milk enriched with buttermilk. The concentrates from skim milk were lower in all fat components and higher in proteins, except for the membrane-associated protein. The buttermilk-enriched samples had the most membrane-associated components. The concentrates from whole milk and buttermilk-enriched, skim milk were similar in protein composition, except for membrane-associated protein. The whole milk samples had the highest concentrations of total and free fat components. Lactose content and mineral composition were similar for the three types of concentrates. Thermal properties and denaturation kinetics were examined by differential scanning calorimetry. The samples exhibited a single broad endothermic peak with the denaturation temperature near 76°C and the enthalpy ranging from 1.86 to 2.16 cal/g. The concentrates from skim milk had higher denaturation enthalpy, whereas the concentrates from buttermilk-enriched, skim milk had slightly higher thermal stability. The overall denaturation process for whey proteins followed the reaction order n = 1.5 with an activation energy ranging from 217 to 251 kJ/mol. The thermal properties were observed to be related to a number of compositional factors. The denaturation enthalpy was positively correlated with β-lactoglobulin and protein content, and negatively correlated with bound fat, membrane protein, and membrane-associated lipid components. The denaturation temperature correlated positively with phospholipid content, and the onset denaturation temperature correlated positively with iron content