Improving drying characteristics and quality attributes of edible bird’s nest (EBN) processed under intermittent IR-UVC assisted drying

The quality of Malaysian edible bird’s nest (EBN) is still regarded inferior due to issues related to nitrite content. In August 2011, the Chinese government imposed a ban on EBN products imported from Malaysia, due to the high level of detectable nitrite (NO2-). This nitrite contamination issue has made a great impact to the edible bird’s industry whereby many EBN farmers, traders and exporters are severely affected. In 2012, the China-Malaysia negotiations agreed on the use of radio frequency identification (RFID) tags on every individual package of Malaysian EBN and set the allowable nitrite limit to be less than 30 ppm, in order to allow exportation of Malaysian EBN to China. The processing methods in EBN industry still remain crude and lack of any form of technology advancement. The purpose of this study was to investigate infrared (IR) coupled with ultraviolet C (UVC) assisted intermittent drying as a mean of EBN processing in order to preserve its nutraceutical properties, ensure nitrite content less than 30 ppm and enhance the commercial value of the dried EBN products. In the present study, EBN were dried by IR assisted drying at low temperature (25°C, 26.7% RH and intermittency =1.00), UVC assisted drying at low temperature (25°C, 26.7% RH and intermittency=1.00) and IR-UVC assisted drying (25°C-40°C, 16.5%-26.7% RH and intermittency=0.20-1.00), respectively. Both engineering properties (drying kinetics, effective moisture diffusivity and effective thermal diffusivity) and quality properties (colour, nitrite content, moisture reabsorption ability, shrinkage, sialic acid retention, antioxidant retention and storage stability) of all dried products were assessed and evaluated. The comparisons were made against samples from fan assisted drying and hot air drying. The results revealed that intermittent infrared (IR) coupled with ultraviolet C (UVC) assisted drying at temperature of 40°C (IR-UVC40) with intermittency

Improving drying characteristics and quality attributes of edible bird’s nest (EBN) processed under intermittent IR-UVC assisted drying

The quality of Malaysian edible bird’s nest (EBN) is still regarded inferior due to issues related to nitrite content. In August 2011, the Chinese government imposed a ban on EBN products imported from Malaysia, due to the high level of detectable nitrite (NO2-). This nitrite contamination issue has made a great impact to the edible bird’s industry whereby many EBN farmers, traders and exporters are severely affected. In 2012, the China-Malaysia negotiations agreed on the use of radio frequency identification (RFID) tags on every individual package of Malaysian EBN and set the allowable nitrite limit to be less than 30 ppm, in order to allow exportation of Malaysian EBN to China. The processing methods in EBN industry still remain crude and lack of any form of technology advancement. The purpose of this study was to investigate infrared (IR) coupled with ultraviolet C (UVC) assisted intermittent drying as a mean of EBN processing in order to preserve its nutraceutical properties, ensure nitrite content less than 30 ppm and enhance the commercial value of the dried EBN products. In the present study, EBN were dried by IR assisted drying at low temperature (25°C, 26.7% RH and intermittency =1.00), UVC assisted drying at low temperature (25°C, 26.7% RH and intermittency=1.00) and IR-UVC assisted drying (25°C-40°C, 16.5%-26.7% RH and intermittency=0.20-1.00), respectively. Both engineering properties (drying kinetics, effective moisture diffusivity and effective thermal diffusivity) and quality properties (colour, nitrite content, moisture reabsorption ability, shrinkage, sialic acid retention, antioxidant retention and storage stability) of all dried products were assessed and evaluated. The comparisons were made against samples from fan assisted drying and hot air drying. The results revealed that intermittent infrared (IR) coupled with ultraviolet C (UVC) assisted drying at temperature of 40°C (IR-UVC40) with intermittency

Unitary Constraints on Semiclassical Schwarzschild Black Holes in the Presence of Island

We reconsider $D\geq4$ dimensional asymptotically flat eternal Schwarzschild black hole, and focus on the situation where the inner boundary of the radiation region is chosen to be near the horizon (i.e. $\beta\ll 1$). The tension between the near horizon condition and the short-distance approximation emerges in large dimensions in previous papers. We remove this tension by introducing a more proper near horizon condition, thus the resulting island solution is well-behaved in any $D\geq4$ dimensional spacetime. Interestingly, a novel constraint is obtained in this situation as required by the existence of the island solution, which directly leads to the constraints on the size of the Schwarzschild black hole, the position of the inner boundary for the radiation region, or the value of $c\cdot\tilde{G}_{N}$ in any $D\geq4$ dimension. When considering the large $D$ limit, the constraint on the size of the Schwarzschild black hole obtained in this situation is in agreement with the result given in $[Phys.Rev.D 102 (2020) 2, 026016]$. We interpret these as the unitary constraints implied by the presence of island in semiclassical gravity.Comment: 21 pages, 4 figures; new contents added in Section 3.2 to derive the constraint, also many related modification

ER stress response plays an important role in aggregation of α-synuclein

<p>Abstract</p> <p>Background</p> <p>Accumulation of filamentous α-synuclein as Lewy bodies is a hallmark of Parkinson's disease. To identify the mechanisms involved in α-synuclein assembly and determine whether the assemblies are cytotoxic, we developed a cell model (3D5) that inducibly expresses wild-type human α-synuclein and forms inclusions that reproduce many morphological and biochemical characteristics of Lewy bodies. In the present study, we evaluated the effects of several histone deacetylase inhibitors on α-synuclein aggregation in 3D5 cells and primary neuronal cultures. These drugs have been demonstrated to protect cells transiently overexpressing α-synuclein from its toxicity.</p> <p>Results</p> <p>Contrary to transient transfectants, the drug treatment did not benefit 3D5 cells and primary cultures. The treated were less viable and contained more α-synuclein oligomers, active caspases 3 and 9, as well as ER stress markers than non-treated counterparts. The drug-treated, induced-3D5 cells, or primary cultures from transgenic mice overexpressing (<2 fold) α-synuclein, displayed more α-synuclein oligomers and ER stress markers than non-induced or non-transgenic counterparts. Similar effects were demonstrated in cultures treated with tunicamycin, an ER stressor. These effects were blocked by co-treatment with salubrinal, an ER stress inhibitor. In comparison, co-treatment with a pan caspase inhibitor protected cells from demise but did not reduce α-synuclein oligomer accumulation.</p> <p>Conclusions</p> <p>Our results indicate that an increase of wild-type α-synuclein can elicit ER stress response and sensitize cells to further insults. Most importantly, an increase of ER stress response can promote the aggregation of wild type α-synuclein.</p

Kinetic retention of sialic acid and antioxidants in Malaysian edible bird's nest during low-temperature drying

Drying is one of the essential processing steps for dried edible bird’s nest; however, sialic acid and antioxidant can be highly thermosensitive and unstable. Therefore, aim of this study was to determine the degradation kinetics of sialic acid and antioxidants during low-temperature drying at 25–40°C as compared to conventional hot air-drying at 70°C. These compounds’ degradation exhibited first-order kinetics. Sialic acid and antioxidant retentions were 83.9 and 96.6%, respectively, at 25°C, and 78.7 and 91.5% at 40°C, respectively, by low-temperature drying; while, 42.5 and 38.7%, respectively, at 70°C by conventional hot air-drying. Finally, empirical models were significantly fitted to predict sialic acid and antioxidant retention as edible bird’s nest reached a certain level of drying, which may be useful from the processing standpoint and validate the usage of low-temperature drying as a process tool for retention of sialic acid and antioxidant in edible bird’s nest

A comparative quality study and energy saving on intermittent heat pump drying of Malaysian edible bird's nest

This paper aims to study the influence of temperature and relative humidity (RH) during intermittent heat pump drying at 28.6–40.6°C, 16.2–26.7% RH, α = 0.2–1.0, and the comparison was made against fan drying (27°C, 39.7% RH, α = 1.00). It was observed that the effects of temperature and RH on drying rate were significant when moisture content was high. Experimental results showed that intermittent heat pump drying at 28.6°C, 26.7% RH, α = 0.2 of edible bird’s nest greatly reduced effective drying time by 84.2% and color change compared to fan drying, and retained the good energy efficiency

Retention of sialic acid content in Malaysian edible bird's nest by heat pump drying

This paper presents the results of an experimental attempt to improve the drying kinetics for the retention of colour and sialic acid in edible bird’s nest through heat pump drying. Kinetics of hot air drying and heat pump drying were studied by performing various drying trials on edible bird’s nest. Isothermal drying trials were conducted in hot air drying and heat pump drying at a temperature range of 40 °C-90 °C and 28.6 °C-40.6 °C, respectively. Intermittent drying trials were carried out in heat pump drying with two different modes, which are periodic air flow supply and step-up air temperature. Experimental results showed that heat pump drying with low temperature dehumidified air not only enhanced the drying kinetics but also produced a stable final product of edible bird’s nest. Heat pump-dried edible bird’s samples retained a high concentration of sialic acid when an appropriate drying mode was selected