scholarly journals Candelilla-shellac: An Alternative Formulation for Coating Apples

HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 691-693 ◽  
Author(s):  
Victorine Alleyne ◽  
Robert D. Hagenmaier
Keyword(s):  
Weight Loss ◽  
Steady State ◽  
Respiration Rate ◽  
Storage Period ◽  
Experimental Period ◽  
Quality Attributes ◽  
Alternative Formulation ◽  
Period Analysis ◽  
Fruit Respiration

An experimental candelilla-shellac formulation for coating apples (Malus ×domestica Borkh.) was developed and compared with commercial shellac-based and carnauba-shellac-based coatings on `Gala' and `Delicious' apples by determining effects on quality attributes, respiration, and internal atmospheres. Fruit were stored at 5 °C for 7 days followed by storage at 21 °C for 14 days. Gloss of `Delicious' apples coated with candelilla-shellac formulations containing 7% to 34% shellac increased with increasing shellac concentrations. `Gala' and `Delicious' apples coated with a candelilla formulation containing 34% shellac maintained quality similar to those coated with commercial carnauba-shellac-based coatings, as indicated by gloss, firmness, internal CO2, O2 and ethanol levels, steady-state respiration rate, weight loss, and flavor. By comparison, shellac-coated fruit maintained the highest gloss throughout the experimental period. Shellac-coated apples were also firmer, contained more ethanol, and received higher flavor scores than did apples receiving other coating treatments. Gloss of all coated fruit decreased with time, although shellac-coated fruit lost less gloss over the 21-day storage period. Analysis of gloss, firmness, fruit respiration, ethanol, weight loss, and flavor demonstrate that the candelilla formulation containing 34% shellac is competitive with current commercial carnauba-based apple-coating products.

scholarly journals 370 Alternative Coating Formulations for Apples and Their Effects on Quality

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 507D-507
Author(s):  
V. Alleyne ◽  
E.A. Baldwin ◽  
R. D. Hagenmaier
Keyword(s):  
Weight Loss ◽  
Cold Storage ◽  
Storage Period ◽  
Quality Attributes ◽  
Deionized Water ◽  
Water Control ◽  
Volatile Composition ◽  
Carnauba Wax ◽  
Coating Formulations

Experimental formulations of candelilla, zein, and polyvinylacetate (PVA) were investigated as alternatives to commercial apple-coating formulations of shellac and carnauba wax. Coatings or a deionized water control were applied to `Red Delicious' apples. Effects on quality attributes, internal atmospheres, sensory flavor, and volatile composition were evaluated. Treated fruit were stored at 5 °C for 7 days followed by 14 days at 21 °C. Zein and PVA formulations exhibited gloss levels comparable with commercial formulations. Although shellac-coated apples maintained the highest gloss over the 21-day storage period, gloss of zein-coated apples was comparable to shellac after fruit were removed from storage at 5 °C. On removal from cold storage there was no difference in firmness among coated and uncoated apples, but, after a 14-day period at 21 °C, shellac-coated fruit were significantly firmer than all other treatments. Shellac- and candelilla-coated apples contained higher CO2 than uncoated fruit and lower O2 than all coated fruit except those coated with PVA. PVA-coated apples contained significantly higher ethylene than uncoated fruit. Candelilla coating was most effective in reducing weight loss while PVA and zein had no effect. Shellac and carnauba coatings reduced weight loss relative to uncoated fruit. There were no differences in perception of sweetness, acidity, off-flavor, and overall flavor. Effects of coating formulations on apple flavor volatile composition will be discussed.

Use of Modified Atmosphere Packaging with Microperforated Polypropylene Films to Maintain Postharvest Loquat Fruit Quality

2008 ◽  
Vol 14 (1) ◽  
pp. 95-103 ◽  
Author(s):  
A. Amorós ◽  
M.T. Pretel ◽  
P.J. Zapata ◽  
M.A. Botella ◽  
F. Romojaro ◽  
...  
Keyword(s):  
Weight Loss ◽  
Steady State ◽  
Modified Atmosphere Packaging ◽  
Storage Period ◽  
Quality Parameters ◽  
Eriobotrya Japonica ◽  
Modified Atmosphere ◽  
Quality Maintenance ◽  
Color Evolution ◽  
Subsequent Period

Loquat fruits (Eriobotrya japonica Lindl cv. `Algerie') were stored in modified atmosphere packaging (MAP), using five types of microperforated polypropylene (PP) films during 2, 4, and 6 weeks at 2 °C and for a subsequent period of 4 days at 20 °C shelf life (SL) out of the bags. Loquat fruits stored without packaging and in normal air served as control. The atmosphere composition at the steady state depended on the film permeability, ranging from 1.2 to 8.5 kPa for CO2 and from 19.5 to 13 kPa for O2 as film permeability decreased. Weight loss was drastically reduced by MAP conditions. Softening, color evolution, and decreases in sugars and organic acids were delayed, these effects also being evident after the SL period. Scores for visual aspect and facility of peeling were also higher for loquat stored in MAP than for controls. Taking into account results form all quality parameters, the most suitable atmosphere for loquat storage was found to be around 2—4 and 16—18 kPa for CO2 and O2, respectively, reached in the PA-80 and PA-60 films. In addition, the storage period for optimum loquat quality maintenance was established as 2 weeks of cold storage plus SL for control fruits, while under MAP conditions, storage periods could be extended up to 6 weeks plus SL, especially using PA-80 and PA-60 films.

Prediction of Tire Tread Wear with FEM Steady State Rolling Contact Simulation

2003 ◽  
Vol 31 (3) ◽  
pp. 189-202 ◽  
Author(s):  
D. Zheng
Keyword(s):  
Weight Loss ◽  
Steady State ◽  
Cross Section ◽  
Rolling Contact ◽  
Dynamic Simulations ◽  
Element Analysis ◽  
Vehicle Acceleration ◽  
Steady State Rolling ◽  
Driving Conditions ◽  
Rate Profile

Abstract A procedure based on steady state rolling contact Finite Element Analysis (FEM) has been developed to predict tire cross section tread wear profile under specified vehicle driving conditions. This procedure not only considers the tire construction effects, it also includes the effects of materials, vehicle setup, test course, and driver's driving style. In this algorithm, the vehicle driving conditions are represented by the vehicle acceleration histogram. Vehicle dynamic simulations are done to transform the acceleration histogram into tire loading condition distributions for each tire position. Tire weight loss rates for different vehicle accelerations are generated based on a steady state rolling contact simulation algorithm. Combining the weight loss rate and the vehicle acceleration histogram, nine typical tire loading conditions are chosen with different weight factors to represent tire usage conditions. It is discovered that the tire tread wear rate profile is changing continuously as the tire is worn. Simulation of a new tire alone cannot be used to predict the tire cross-section tread wear profile. For this reason, an incremental tread wear simulation procedure is performed to predict the tire cross section tread wear profile. Compared with actual tire cross-section tread wear profiles, good results are obtained from the simulations.

Validation of On-line Respiration Meter and its Applications by Computer Simulation

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1355-1363 ◽  
Author(s):  
C-W. Kim ◽  
H. Spanjers ◽  
A. Klapwijk
Keyword(s):  
Steady State ◽  
Activated Sludge ◽  
Respiration Rate ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Mass Balances ◽  
Short Term ◽  
Respiration Rates ◽  
On Line ◽  
Made In

An on-line respiration meter is presented to monitor three types of respiration rates of activated sludge and to calculate effluent and influent short term biochemical oxygen demand (BODst) in the continuous activated sludge process. This work is to verify if the calculated BODst is reliable and the assumptions made in the course of developing the proposed procedure were acceptable. A mathematical model and a dynamic simulation program are written for an activated sludge model plant along with the respiration meter based on mass balances of BODst and DO. The simulation results show that the three types of respiration rate reach steady state within 15 minutes under reasonable operating conditions. As long as the respiration rate reaches steady state the proposed procedure calculates the respiration rate that is equal to the simulated. Under constant and dynamic BODst loading, the proposed procedure is capable of calculating the effluent and influent BODst with reasonable accuracy.

scholarly journals Chitosan Films Obtained from Brachystola magna (Girard) and Its Evaluation on Quality Attributes in Sausages during Storage

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1782
Author(s):  
Juan Manuel Tirado-Gallegos ◽  
Paul Baruk Zamudio-Flores ◽  
Miguel Espino-Díaz ◽  
René Salgado-Delgado ◽  
Gilber Vela-Gutiérrez ◽  
...  
Keyword(s):  
Weight Loss ◽  
Lipid Oxidation ◽  
Meat Products ◽  
Water Vapor Permeability ◽  
Good Alternative ◽  
Quality Attributes ◽  
Vapor Permeability ◽  
Biodegradable Films ◽  
Molecular Weights ◽  
Chitosan Films

High molecular weight chitosan (≈322 kDa) was obtained from chitin isolated from Brachystola magna (Girard) to produced biodegradable films. Their physicochemical, mechanical and water vapor permeability (WVP) properties were compared against commercial chitosan films with different molecular weights. Brachystola magna chitosan films (CFBM) exhibited similar physicochemical and mechanical characteristics to those of commercial chitosans. The CFBM films presented lower WVP values (10.01 × 10−11 g/m s Pa) than commercial chitosans films (from 16.06 × 10−11 to 64.30 × 10−11 g/m s Pa). Frankfurt-type sausages were covered with chitosan films and stored in refrigerated conditions (4 °C). Their quality attributes (color, weight loss, pH, moisture, texture and lipid oxidation) were evaluated at 0, 5, 10, 15 and 20 days. Sausages covered with CFMB films presented the lowest weight loss (from 1.24 to 2.38%). A higher increase in hardness (from 22.32 to 30.63 N) was observed in sausages covered with CFMB films. Compared with other films and the control (uncovered sausages), CFMB films delay pH reduction. Moreover, this film presents the lower lipid oxidation level (0.10 malonaldehyde mg/sample kg). Thus, chitosan of B. magna could be a good alternative as packaging material for meat products with high-fat content.

Kinetics of the cytochrome c oxidase and reductase reactions in energized and de-energized mitochondria

1977 ◽  
Vol 55 (7) ◽  
pp. 706-713 ◽  
Author(s):  
Lars Chr. Petersen ◽  
Hans Degn ◽  
Peter Nicholls
Keyword(s):  
Steady State ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Oxygen Concentration ◽  
Respiration Rate ◽  
Redox State ◽  
Rat Liver Mitochondria ◽  
Excess Oxygen ◽  
Succinate Oxidation ◽  
State Reduction

1. Coupled, cytochrome-c-depleted ('stripped') rat liver mitochondria reducing oxygen in the presence of exogenous cytochrome c, with succinate or ascorbate as substrates, show marked declines in the steady-state reduction of cytochrome c in excess oxygen on addition of uncouplers. Calculated ratios of maximal turnover in the uncoupled state and in the energized state for the cytochrome c oxidase (EC 1.9.3.1) reaction lie between 3 and 6, as obtained with reconstituted oxidase-containing vesicles. The succinate-cytochrome c reductase activity in such mitochondria shows a smaller response to uncoupler than that of the oxidase.2. The respiration rates of uncoupled mitochondria oxidizing ascorbate in the presence of added cytochrome c follow a Michaelis–Menten relationship with respect to oxygen concentration, in accordance with the pattern found previously with the solubilized oxidase. But succinate oxidation tends to give nonlinear concave-upward double-reciprocal plots of respiration rate against oxygen concentration, in accordance with the pattern found previously with intact uncoupled mitochondria.3. From simultaneous measurements of cytochrome c steady-state reduction, respiration rate, and oxygen concentration during succinate oxidation under uncoupled conditions it is found that at full reduction of cytochrome c, apparent Km for oxygen is 0.9 μM and the maximal oxidase (aa3) turnover is 400 s−1 (pH 7.4, 30 °C).4. The redox state of cytochrome c in uncoupled systems reflects a simple steady state; the redox state of cytochrome c in energized systems tends towards an equilibrium condition with the terminal cytochrome a3, whose apparent potential under these conditions is more negative than that of cytochrome c.

Effect of growth rate on the physiological rates of a chemostat-grown rotifer Encentrum linnhei

1988 ◽  
Vol 68 (1) ◽  
pp. 165-177 ◽  
Author(s):  
J. M. Scott
Keyword(s):  
Growth Rate ◽  
Oxygen Consumption ◽  
Steady State ◽  
Respiration Rate ◽  
Clearance Rate ◽  
Ingestion Rate ◽  
Physiological State ◽  
Growth Efficiency ◽  
Theoretical Figure ◽  
Marine Rotifer

The physiological rates of a normally omnivorous marine rotifer, Encentrum linnhei, were measured under the steady-state chemostat conditions in which the physiological state of the food-algae was kept constant whilst the rotifer growth rate was changed to preset levels. The specific clearance rate ranged between 50 and 100 μl/μg rotifer C/day (1.5–3.0 μ/rot/day) and varied hyperbolically with growth rate, a similar curve was obtained with the specific ingestion rate which varied between 1–2 μg C/μg rot C/day. A mean respiration rate of 0.45 μg C/μg rot C/day was obtained from oxygen consumption measurements. About 60‰ of ingested energy was found to be egested as paniculate matter and 9–4 °0 dissipated as heat, the latter comparing with a theoretical figure of 4–5‰.From rates, transfer efficiencies were obtained giving a mean net growth efficiency (K2) of 38‰ and a mean overall growth efficiency (K1 of 15‰. A curvilinear increase of Kl with growth rate contrasts with linear and hyperbolic responses found with brachionid rotifers.

Validation of a new method for determination of free fatty acid turnover

1987 ◽  
Vol 252 (3) ◽  
pp. E431-E438 ◽  
Author(s):  
J. M. Miles ◽  
M. G. Ellman ◽  
K. L. McClean ◽  
M. D. Jensen
Keyword(s):  
Steady State ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Clearance Rate ◽  
Experimental Period ◽  
Metabolic Clearance ◽  
Metabolic Clearance Rate ◽  
State Equations ◽  
Tracer Methods

The accuracy of tracer methods for estimating free fatty acid (FFA) rate of appearance (Ra), either under steady-state conditions or under non-steady-state conditions, has not been previously investigated. In the present study, endogenous lipolysis (traced with 14C palmitate) was suppressed in six mongrel dogs with a high-carbohydrate meal 10 h before the experiment, together with infusions of glucose, propranolol, and nicotinic acid during the experimental period. Both steady-state and non-steady-state equations were used to determine oleate Ra ([3H]oleate) before, during, and after a stepwise infusion of an oleic acid emulsion. Palmitate Ra did not change during the experiment. Steady-state equations gave the best estimates of oleate inflow approximately 93% of the known oleate infusion rate overall, while errors in tracer estimates of inflow were obtained when non-steady-state equations were used. The metabolic clearance rate of oleate was inversely related to plasma concentration (P less than 0.01). In conclusion, accurate estimates of FFA inflow were obtained when steady-state equations were used, even under conditions of abrupt and recent changes in Ra. Non-steady-state equations, in contrast, may provide erroneous estimates of inflow. The decrease in metabolic clearance rate during exogenous infusion of oleate suggests that FFA transport may follow second-order kinetics.

Note. Effect of Storage Temperature on the Shelf Life of Hass Avocado (Persea Americana)

2004 ◽  
Vol 10 (2) ◽  
pp. 73-77 ◽  
Author(s):  
K. Perez ◽  
J. Mercado ◽  
H. Soto-Valdez
Keyword(s):  
Weight Loss ◽  
Shelf Life ◽  
Respiration Rate ◽  
Ethylene Production ◽  
Storage Temperature ◽  
Persea Americana ◽  
Co2 Production ◽  
Hass Avocado ◽  
Storage Temperatures

The effect of storage temperature on the shelf life, weight loss, respiration rate and ethylene production of Hass avocado (Persea americana Mill) was studied. Two batches of green mature avocado fruits, classified as ‘‘super extra’’ were stored at 10 and 20 C (first batch) and at 7 and 25 C (second batch). The avocado shelf lives were 22, 8, 32 and 6 days at 10, 20, 7 and 25 C, respectively. Based on the data of the first assay Q10 was calculated as 2.75, with this value the predicted shelf life at 7 and 25 C were 29.8 and 4.8 days, respectively. That meant shelf life was underestimated 7 and 20% at 7 and 25 C, respectively. Weight loss was linear at both the storage temperatures, it was 4.3% in fruits at 20 C for 8 days and 3.0% at 10 C for 22 days. The maximum CO2 production at 20 C was reached during the second day of storage, while at 10 C it was reached at the 17th day (176.17 15.98 and 74.73 7.32 mL/kg h, respectively). The maximum ethylene production at 20 C was reached the second day of storage, and at 10 C the 6th day (239.06 54.55 and 28.00 8.12 mL/kg h, respectively).

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