RESIDUAL GAS VOLUME EFFECT ON QUALITY OF RETORT POUCH WET‐PACK PEARS

The apparent diffusion coefficient (ADC) of hyperpolarized (HP) gases is a parameter that reflects changes in lung microstructure. However, ADC is dependent on many physiological and experimental variables that need to be controlled or specified in order to ensure the reliability and reproducibility of this parameter. A single breath-hold experiment is desirable in order to reduce the amount of consumed HP gas. The application of a positive end-expiratory pressure (PEEP) causes an increase in the residual gas volume. Depending on the applied PEEP, the ratio between the incoming and residual gas volumes will change and the ADC will vary, as long as both gases do not have the same diffusion coefficient. The most standard method for human applications uses air for breathing and a bolus of pure HP (3)He for MRI data acquisition. By applying this method in rats, we have demonstrated that ADC values are strongly dependent on the applied PEEP, and therefore on the residual gas volume in the lung. This outcome will play an important role in studies concerning certain diseases, such as emphysema, which is characterized by an increase in the residual volume. Ventilation with an oxygen-helium mixture (VOHeM) is a proposed single breath-hold method that uses two different gas mixtures (O(2)-(4)He for ventilation and HP (3)He-N(2) for imaging). The concentration of each gas in its respective mixture was calculated in order to obtain the same diffusion coefficient in both mixtures. ADCs obtained from VOHeM are independent of PEEP, thus minimizing the effect of the different residual volumes.

Understanding the degradation of ascorbic acid and glutathione in relation to the levels of oxidative stress biomarkers in broccoli (Brassica oleracea L. italica cv. Bellstar) during storage and mechanical processing

Free residual gas after laparoscopy may cause shoulder pain, decreasing patient satisfaction with the procedure. We analyzed the correlation between postoperative residual carbon dioxide gas and shoulder pain, explored the peri- and postoperative factors associated with residual carbon dioxide and determined the effects of the use of a drainage tube. A cohort of 326 patients who underwent laparoscopic adnexal surgery between March 2005 and June 2018 at a teaching hospital in Korea was retrospectively analyzed through a medical records review. The enrolled patients were divided into 1-, 2-, and 3-port groups. The right volume, left volume, and total volume of residual gas were calculated using a formula based on measurements obtained from chest X-rays. Continuous variables were compared using Student t tests. Categorical variables were compared with the chi-square test or Kruskal–Wallis test. The total volumes of postoperative residual carbon dioxide gas were significantly different between the 1- and 2-port groups and between the 1- and 3-port groups (157.3 ± 179.2 vs 25.1 ± 92.3 mL and 157.3 ± 179.2 vs 12.9 ± 36.4 mL, respectively). The volume of residual gas and the time to the first passage of gas were positively correlated. The total volume of residual gas was more strongly correlated with the operative wound pain score than with the shoulder pain score. Additionally, the pre- and postoperative white blood cell counts, postoperative hospitalization duration, residual carbon dioxide volume, and shoulder pain score were significantly different between patients with and without a drainage tube. Although the volume of residual gas was not correlated with the shoulder pain score, the author found that both were lower in patients with a drainage tube than in those without, indicating that a drainage tube could be safely used to decrease residual gas volume and the shoulder pain score without increasing the risk of postoperative infection.

This study aimed to compare the effect of ohmic and conventional heat treatments on red guava pulp, evaluating the effects on pulp color, degradation kinetics of ascorbic acid and carotenoids, together with the thermal efficiency of both treatments. Samples were heated by conventional heating (water bath) and ohmic heating (platinum electrodes) using alternating voltage of 21.2 V/m and average frequency of 60 Hz at temperatures of 60, 70 and 80 °C for 110 min. In general, the ascorbic acid degradation followed a first order kinetics, for both heat treatments, the pulp color showed no significant variation (p < 0.05) according to the type and time of heating applied, whereas the carotenoid content was favored by ohmic heating, at the two lowest temperatures tested. As for the heat transfer process, the ohmic treatment showed an average thermal efficiency of 40.93%, while the conventional heating, 2.62%, proving to be a promising emerging technology for processing viscous foods with suspended particles like fruit pulps.

Ascorbic acid occurs naturally in many wine-making fruits. The industry also uses ascorbic acid as an antioxidant and color stabilizer in the making of alcoholic beverages including white wine, wine cooler, alcopop, and fruit liqueur. However, the degradation of ascorbic acid itself may cause browning and the deterioration of color quality. This study was aimed to monitor the degradation of ascorbic acid, the formation of degradation products, and the browning in storage of ascorbic acid containing 0-40% (v/v) ethanolic solutions buffered at pH 3.2 as models of alcoholic beverages. The results show that ascorbic acid degradation in the ethanolic solutions during storage follows first-order reaction, that the degradation and browning rates increase with the increase of ethanol concentration, that the activation energy for the degradation of ascorbic acid is in the range 10.35-23.10 (kcal/mol), that 3-hydroxy-2-pyrone is an indicator and a major product of ascorbic acid degradation, and that aerobic degradation pathway dominants over anaerobic pathway in ascorbic acid degradation in ethanolic solutions.

Evaluation of ascorbic acid and sugar degradation products during fruit dessert processing under conventional or ohmic heating treatment

The kinetics of ascorbic acid (AA) degradation and nonenzymatic browning (NEB) of heat-treated single strength orange juice (OJ) over a temperature between 70-95 oC for 2-10 min. and stored under opaque condition at 4 and 20 oC for 2 months have been studied. Analysis of kinetic data by measuring absorbance at 420 nm (A420) suggested a zero-order reaction for NEB, while AA degradation followed a first-order reaction. The temperature dependence of NEB and AA degradation were adequately modeled by the Arrhenius equation. Activation energy of NEB and AA degradation as affected by heat-treatment and storage condition followed the same trend. The obtained results indicate that AA degradation can be evaluated by the intensity of brown colour development of OJ.

Kinetics of ascorbic acid degradation in fruit-based infant foods during storage

Vitamin C loss kinetics and shelf life study in fruit-based baby foods during post packaging storage

Ascorbic acid (vitamin C) degradation during electrical and conventional heating was studied to determine if the presence of an electric field altered the rate of degradation. Experiments were peiformed using a static ohmic heating apparatus, and heating histories were matched using applied voltage in the electrical case and hot oil in the conventional case. A statistical analysis showed that electric field has no significant effect on ascorbic acid degradation. Pseudo first order degradation kinetics were observed for both conventional and ohmic cases. the activation energy and frequency factor for the conventional case was 12.6 kcal/mol and 19.95 × 105 min-1, respectively; for the ohmic case, values were 12.5 kcal/mol and 19.59 × 1O5 min-1. the effect of electrolysis on ascorbic acid degradation was also examined. Gas production and dissolution appeared

The aim of the current study was to directly investigate whether active gas suction reduces intraperitoneal residual carbon dioxide and to analyze the effect of active gas suction on postoperative pain after laparoscopic cholecystectomy. This prospective, randomized clinical study included patients between 19 and 65 years of age with gallbladder disease who were eligible for elective laparoscopic cholecystectomy. Patients were allocated into either the natural evacuation group (NE group) or the active suction group (AS group). In the AS group, active suction was applied by inserting the laparoscopic suction irrigation device through a 5-mm trocar for 60 seconds at the end of surgery. A chest X-ray was taken at postoperative Day 1, and the residual intraabdominal gas volume was measured. Perioperative data including pain score and analgesic requirement were collected. Thirty-nine patients were allocated to the NE group, and 36 were allocated to the AS group. There was no statistically significant difference between the two groups in terms of demographic data and operative findings. However, a significant difference was observed in the residual intraperitoneal gas volume, with 15.9±6.8 mL in the NE group and 6.7±4.0 mL in the AS group (P<.001). Significant differences were also observed in the pain scores measured 6 hours after surgery, on postoperative Day 1, and on postoperative Day 2. Active gas suction is a very simple procedure that is safe and feasible. Performing this procedure significantly decreases the residual intraperitoneal gas volume and postoperative pain after laparoscopic surgery.

Ultraviolet radiation induced degradation of ascorbic acid in a model apple juice system and in apple juice was studied using a collimated beam batch UV reactor. In the model system, ascorbic acid degradation was more rapid at higher dose levels and the reaction accelerated with increasing exposure time. Ascorbic acid degradation significantly (P < 0.05) increased as the pH was raised from 2.4 to 5.5, although no difference was observed between 2.4 and 3.3. Increasing malic acid concentration between 0.1 and 1%, increased ascorbic acid degradation (P < 0.05) although there was no difference between 0.5 and 1.0%. Solution absorbance, varied by addition of tannic acid, decreased ascorbic acid degradation with increasing concentration due to absorption of UV radiation. Fructose at levels found in apple juice significantly increased ascorbic acid degradation while glucose and sucrose did not. Factors identified that accelerate ascorbic acid degradation may at least partially explain why ascorbic acid degradation occurred more rapidly in UV-treated apple juice than in the 0.5% malic acid model system. Ascorbic acid degradation continued after UV treatments during dark storage. Storage decreases were faster at higher initial UV dose levels and higher storage temperature. The present study shows the effect of UV processing on ascorbic acid, a key vitamin found in many fruit juices. Process developers and researchers can use this study as a model for designing experiments to identify factors that influence the stability of vitamin C and other bioactive compounds during UV processing.

Evaluation of non-thermal effects of electricity on ascorbic acid and carotenoid degradation in acerola pulp during ohmic heating

In this study, the effect of drying temperature on the degradation of ascorbic acid in cornelian cherry fruit was investigated. Cornelian cherry fruits were dried as single layer in a convective dryer at different air temperatures (50, 60, and 70°C) and 1 m s-1 constant air velocity. Increasing drying temperature increased ascorbic acid degradation. As the temperature increased from 50°C to 70°C, degradation of ascorbic acid increased from 42±0.59% to 49±0.73%. The degradation kinetics of ascorbic acid was investigated according to the zero-order, first-order, and Weibull model. It was observed that the best fitting model for ascorbic acid degradation kinetics was the first order kinetic model. Kinetic parameters such as D, t1/2, and Q10 were calculated using the rate constant of the first-order model. The increased temperature increased the value of degradation and decreased half-life time. The value of Q10 (50°C-60°C) was greater than value of Q10 (60°C-70°C). Thermodynamic results indicated that the degradation of ascorbic acid in cornelian cherry was non-spontaneous, endothermic and irreversible.

ABSTRACTSpinach was baked in steam-assisted hybrid ovens, natural and forced convection ovens, and saturated steam ovens at different temperatures and baking times. The moisture content, water activity, peroxidise activity, colour, ascorbic acid, and chlorophyll content were determined for each baking time and kinetic analysis of thermal degradation of the colour, chlorophyll, and ascorbic acid were evaluated. Degradation of green colour, total chlorophyll, and ascorbic acid in spinach leaves during the baking process was considered as first order reaction kinetics and temperature dependency of degradation was described by the Arrhenius equation. Baking in steam-assisted hybrid ovens resulted in the highest rate of reaction for both colour change and chlorophyll degradation, followed by forced convection and then natural convection ovens. The existence of steam in the baking chamber resulted in an acceleration of the baking process and better ascorbic acid retention in spinach was determined by baking in steam-assisted hybrid ovens. Degradation kinetics could allow definition of optimum baking temperatures and times in different types of ovens and shorter baking times should be preferred in steam-assisted hybrid ovens if fresh appearance (high greenness) is desired.