Effects of High Temperature and Relative Humidity on Mold Content and Quality of Stored Popcorn†

1995 ◽  
Vol 58 (9) ◽  
pp. 1018-1022 ◽  
Author(s):  
SARATH K. KATTA ◽  
LLOYD B. BULLERMAN

White and yellow popcorn were stored in different containers at high temperature (35°C) and high relative humidity (85%) conditions for 3 months. Gradual decreases in popping volumes with the lengthening of storage time were observed in both white and yellow popcorn. Internal mold infection was quite low in both white (5.7%) and yellow (3.0%) popcorn at the beginning of storage tests. Few differences were found in total infection levels up to 60 days of storage, except that the Aspergillus glaucus group became established in place of field fungi. A gradual increase in mold infection levels was then observed during the remaining 30 days of storage. Visible mold growth was also observed on the tips of some kernels by the end of storage studies. Internal mold infection in white popcorn stored in an open container was lower (18.3%) than white popcorn stored in a closed plastic bag (75.0%) and closed plastic jar (85.3%), whereas the internal mold infection in yellow popcorn stored in an open container was higher (23.3%) than yellow popcorn stored in a closed plastic bag (6.3%) and closed plastic jar (2.6%). The A. glaucus group were the predominant molds found at the end of storage tests. The ability of toxigenic molds to invade the popcorn was determined using a dry spore inoculum. None of the inoculated molds, which included Aspergillus flavus, Penicillium martensii, and Penicillium viridicatum, were able to invade the popcorn during storage. However, the A. glaucus group predominated at the end of storage tests in the inoculated samples.

1989 ◽  
Vol 69 (4) ◽  
pp. 955-961 ◽  
Author(s):  
L. F. LAFLAMME

Two experiments were conducted to assess the effects of storage conditions on the quality of large round bales (LRB). Samples were taken at 75-d intervals from LRB stored inside, outside single bales covered with a 15-mm black polyethylene plastic bag, outside uncovered as single bales, outside uncovered in a single row and outside uncovered in a double stacked row. Bales were sampled at depths of 0–15, 15–30 and 30–45 cm. Time, storage and depth factors had an influence on the chemical components of the LRB except for protein. Weathering had the most effect after 150 d of storage and with LRB stored uncovered and in the top 15-cm layer. Significant (P < 0.05) interactions in in vitro dry matter digestibilities were found for storage time × depth of sample, storage time × storage methods and for depth of sample × storage methods. Under the conditions of our experiments, weathering damages were limited to the superficial layer of LRB left uncovered. Key words: Large round bales, weathering, storage, moisture


1997 ◽  
Vol 48 (5) ◽  
pp. 625 ◽  
Author(s):  
Roxana Savin ◽  
Peter J. Stone ◽  
Marc E. Nicolas ◽  
Ian F. Wardlaw

Short periods of very high maximum temperature (>35°C) during grain filling appear to reduce grain yield and quality in barley. Tolerance of grain yield and quality to heat stress may be increased when acclimation to high temperature occurs. Two experiments were performed to test the hypothesis that a gradual (or stepped) increase to very high temperature reduces the impact of that stress on grain growth and quality of barley, compared with a sudden increase over the same temperature range. Plants experiencing either a sudden or a gradual increase did not exhibit any differences in grain weight or malting quality, but increasing the temperature in 2 steps (so that plants were exposed to 30 or 34°C for 2 h before a 40°C heat stress) appeared to have produced acclimation, since the reduction in grain weight under the 2-step treatment was about half that of either a sudden or gradual increase in temperature. Heat stress altered grain composition in various ways. The reduction in final grain weight was strongly and linearly related to the reduction in starch content. Grain β-glucan was 4·5 ± 0·5% across treatments and experiments and was significantly reduced in the glasshouse but not in the phytotron experiment. However, β-glucan degradation was similar between treatments in both experiments. Grain nitrogen concentration was very high and similar between treatments. Consequently, diastatic power was high and there was a trend towards a reduction under heat stress. Free amino nitrogen was higher under heat stress, indicating a higher protein modification than in the controls. Malt extract was significantly reduced by heat stress in the glasshouse experiment.


Author(s):  
R M Anderson ◽  
B Bhushan

The effect of environment on the drop-out performance of magnetic tapes in a rotary head-tape drive was studied. A capacitance probe, mounted on the rotating upper drum and positioned to measure tangential deflection of the head, was used to measure friction force. This technique, in conjunction with the measurement of head signal amplitude, was used to investigate the effect of environment on drop-outs. Streaming mode tests were conducted with two brands of S-VHS tapes at various combinations of temperature (6-38 °C) and relative humidity (10-80% RH). From the experiments, it was found that the propensity for intermittent drop-outs increases in a low relative humidity environment. A low relative humidity environment increases the propensity for debris to persist over the head gap and create a loss in the head signal. High temperature further increases the propensity for drop-outs in a low relative humidity environment. The propensity for intermittent drop-outs is reduced by increasing the relative humidity, changing magnetic tapes and to some extent by lowering the temperature of the environment. It was also determined that variability in the quality of magnetic tapes has a significant impact on the number of intermittent and permanent drop-outs encountered during playback.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 890A-890
Author(s):  
Durward Smith ◽  
Joseph D. Norton

Stored Chinese chestnuts (Castanea molissima Blume) are extremely susceptible to spoilage by molds. This research was initiated to determine if storage at reduced atmospheres in conjunction with vacuum-infused mycostatic chemicals could reduce mold growth and enhance the quality of stored nuts. Nuts were treated with two levels of buffered sodium propionate and two levels of buffered sodium benzoate and stored either at atmospheric pressure or at 0.17 atmosphere (4.0% O2) and minimal gas circulation. Relative humidity was maintained at 88%. Mold counts, weight, texture, and moisture content were recorded every 20 days. Mold counts of the chemically treated nuts stored at atmospheric pressure did not differ from untreated nuts. Storage at reduced atmosphere in conjunction with chemical treatment inhibited mold growth, reduced weight loss, and preserved fresh quality and viability of the nuts.


Author(s):  
Gennadiy Valentinovich Alexeev ◽  
Elena Igorevna Verboloz

The article focuses on the process of intensive mixing of liquid phase in the tin during high-temperature sterilization, i.e. sterilization when temperature of the heat carrier reaches 150-160°C. It has been stated that for intensification of the thermal process during sterilization of tinned fish with liquid filling it is preferable to turn a tin from bottom to top. This operation helps to increase the driving power of the process and to shorten warming time. Besides, high-temperature sterilization carried out according to experimental modes, where the number of tin turnovers is calculated, greatly shortens processing time and improves quality of the product. In this case there is no superheating, all tins are evenly heated. The study results will contribute to equipment modernization and to preserving valuable food qualities.


2020 ◽  
Vol 16 (2) ◽  
pp. 18-23
Author(s):  
K. PRAVALLIKA ◽  
C. ARUNKUMAR ◽  
A. VIJAYKUMAR ◽  
R. BEENA ◽  
V. G. JAYALEKSHMI

1995 ◽  
Vol 60 (11) ◽  
pp. 1905-1924 ◽  
Author(s):  
Hong Phuong-Nguyen ◽  
Geneviève Delmas

Dissolution, crystallization and second dissolution traces of isotactic poly(propylene) have been obtained in a slow temperature ramp (3 K h-1) with the C80 Setaram calorimeter. Traces of phase-change, in presence of solvent, are comparable to traces without solvent. The change of enthalpy on heating or cooling, ∆Htotal, over the 40-170 °C temperature range, is the sum of two contributions, ∆HDSC and ∆Hnetwork. The change ∆HDSC is the usual heat obtained in a fast temperature ramp and ∆Hnetwork is associated with a physical network whose disordering is slow and subject to superheating due to strain. When dissolution is complete, ∆Htotal is equal to ∆H0, the heat of fusion of perfect crystals. The values of ∆Htota for nascent and recrystallized samples are compared. Dissolution is the tool to evaluate the quality of the crystals. The repartition of ∆Htotal, into the two endotherms, reflects the quality of crystals. The crystals grown more rapidly have a higher fraction of network crystals which are stable at high T in the solvents. A complete dissolution, i.e. a high temperature (170 °C or more) is necessary to obtain good crystals. The effect of concentration, polymer molecular weight and solvent quality on crystal growth is analyzed.


Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1140
Author(s):  
Huakai Wang ◽  
Pan Yang ◽  
Longxian Li ◽  
Nan Zhang ◽  
Yongxi Ma ◽  
...  

Six types of vitamin K3 (VK3); two sources (menadione sodium bisulfite, MSB; menadione nicotinamide bisulfite, MNB), and three different forms (crystal, micro-capsule, and micro-sphere) were used to determine the retention of VK3 in vitamin premixes (Experiment 1) or vitamin trace mineral (VTM) premixes (Experiment 2) after 1, 2, 3, and 6 months of storage. The retention of VK3 in vitamin premixes was evaluated at 25 °C/60% relative humidity or 40 °C/75% relative humidity in an incubator in Experiment 1 and in VTM premixes (choline chloride: 0 vs. 16,000 mg/kg) stored at room temperature in Experiment 2. The VK3 retention in vitamin premix or VTM premix decreased significantly with the extension of storage time (p < 0.05). In Experiment 1, the VK3 retention was higher in the 25 °C/60% incubator (56%) than in the 40 °C/75% incubator (28%). The MNB retention (52%) was higher than MSB retention (32%). The retention of VK3 in micro-capsules (43%) or micro-spheres (48%) was higher than the crystal form (35%) after six months of storage. In Experiment 2, there was no difference between the retention of MSB (49%) or MNB (47%). The retention of VK3 of micro-capsule (51%) or micro-sphere (54%) was higher than that of crystal form (40%). The VK3 retention was higher in the choline-free group (51%) than in the choline group (47%) after six months of storage. Finally, the predicted equations of VK3 retention with storage time in vitamin premixes or VTM premixes were established. The R2 of the prediction equations was ≥0.9005, indicating that time is an important factor in predicting VK3 retention. In conclusion, the higher temperature-relative humidity, choline had negative effects on VK3 retention during premix storage. MNB retention was higher than MSB during storage of vitamin premix. The encapsulated forms of VK3, micro-capsules and micro-spheres, could improve VK3 storage stability in vitamin premix and VTM premix.


2021 ◽  
Vol 359 ◽  
pp. 129950
Author(s):  
Ai Huang ◽  
Zongde Jiang ◽  
Meng Tao ◽  
Mingchun Wen ◽  
Zhipeng Xiao ◽  
...  

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 928
Author(s):  
Yong Du ◽  
Zhenzhen Kong ◽  
Muhammet Toprak ◽  
Guilei Wang ◽  
Yuanhao Miao ◽  
...  

This work presents the growth of high-quality Ge epilayers on Si (001) substrates using a reduced pressure chemical vapor deposition (RPCVD) chamber. Based on the initial nucleation, a low temperature high temperature (LT-HT) two-step approach, we systematically investigate the nucleation time and surface topography, influence of a LT-Ge buffer layer thickness, a HT-Ge growth temperature, layer thickness, and high temperature thermal treatment on the morphological and crystalline quality of the Ge epilayers. It is also a unique study in the initial growth of Ge epitaxy; the start point of the experiments includes Stranski–Krastanov mode in which the Ge wet layer is initially formed and later the growth is developed to form nuclides. Afterwards, a two-dimensional Ge layer is formed from the coalescing of the nuclides. The evolution of the strain from the beginning stage of the growth up to the full Ge layer has been investigated. Material characterization results show that Ge epilayer with 400 nm LT-Ge buffer layer features at least the root mean square (RMS) value and it’s threading dislocation density (TDD) decreases by a factor of 2. In view of the 400 nm LT-Ge buffer layer, the 1000 nm Ge epilayer with HT-Ge growth temperature of 650 °C showed the best material quality, which is conducive to the merging of the crystals into a connected structure eventually forming a continuous and two-dimensional film. After increasing the thickness of Ge layer from 900 nm to 2000 nm, Ge surface roughness decreased first and then increased slowly (the RMS value for 1400 nm Ge layer was 0.81 nm). Finally, a high-temperature annealing process was carried out and high-quality Ge layer was obtained (TDD=2.78 × 107 cm−2). In addition, room temperature strong photoluminescence (PL) peak intensity and narrow full width at half maximum (11 meV) spectra further confirm the high crystalline quality of the Ge layer manufactured by this optimized process. This work highlights the inducing, increasing, and relaxing of the strain in the Ge buffer and the signature of the defect formation.


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