Search results for "orange"
showing 10 items of 241 documents
In vitro culture of albedo tissue from fruits of Citrus sinensis cv. Washington Navel: Effect of fruit age and orange juice
1994
SUMMARYCallus from citrus fruit explants has been used to study different aspects of fruit physiology. However, growth responses of callus derived from citrus fruit tissues are not always comparable with those of intact fruit; there are, for example, differences in nutritional requirements. Results with tissues cultivated in vitro seem to depend on a variety of environmental and internal factors. In the present work albedo tissue from fruits of Citrus sinensis cv. Washington Navel of different age has been used as a source of explants. The growth (fresh weight) of the calli was dependent on the age of the fruit from which the explants were taken, as well as on the addition of orange juice t…
EFFECT OF PLANT GROWTH REGULATORS AND ORANGE JUICE ON GROWTH OF CALLUS FROM FRUIT TISSUES OF WASHINGTON NAVEL ORANGE
1997
The effect of the plant growth regulators kinetin, gibberellic acid (GA3), and 2,4- dichlorophenoxyacetic acid (2,4-D), either alone or in combination with orange juice, on the in vitro growth of mesocarp and endocarp explants from 90–120 day-old Washington Navel Citrus sinensis orange fruits has been determined. Both fruit tissues formed callus. From endocarp 100% callus was formed in all cultures, even without growth regulators in the culture medium, while callus growth was lower from mesocarp. The addition of orange juice at a final concentration of 15% (v/v) to the basal medium without growth regulators increased the callus growth, specially that derived from endocarp. However, the high…
Incidence of microorganisms from fresh orange juice processed by squeezing machines
2012
Abstract This study was carried out to evaluate the microbiological quality of orange juice obtained from squeezing machines in foodservice establishments. The samples included fresh squeezed orange juice and juice which is maintained in metal jugs until consumption. According to the European Commission Regulation (No. 2073/2005 and No. 1441/2007) and Spanish microbiological criteria (No. 3484/2000), 12% and 43% of the total examined lots exceed the adopted limits of mesophilic aerobic counts and Enterobacteriaceae, respectively. Possibly, this contamination is caused by incorrect handling of oranges and juices and also by inadequate cleaning and sanitization of squeezing machine and metal …
Product information, hedonic evaluation, and purchase decision: an experimental study of orange juice
2007
AbstractTwo randomly sampled groups of subjects were endowed with real budgets and placed in 5 different budget/price situations. In each situation they had to evaluate 6 orange juices and complete a demand table. At the end of the experiment, one demand table was randomly selected and participants had to buy the corresponding products. In one group, participants choose after looking at the packaging in the other they could also taste the products. Results show that participants who chose without tasting, made quicker decisions, selected a larger number of variants and were more influenced by prices than those who could taste the products. Although choices appeared very heterogeneous, most …
Anteroxanthin concentration during refrigerated storage in orange juice treated by PEF
2009
Pulsed Electric Field (PEF) processing inactivates microorganisms without significant adverse effects on flavor and nutrients. In this work was studied the transformations of antheraxanthin and mutatoxanthin when natural orange juice is treated by pasteurisation (90°C, 20 s) or PEF (30 kV/cm, 100 µs), and also its evolution during seven weeks of storage in refrigeration at two different temperatures (2°C and 10°C). The results showed that antheraxanthin concentration decreased during the storage. The decrease was greater in the untreated, pasteurised and PEF-treated orange juices stored at 10°C and this carotenoid was not detected from the 6 th week onwards. The same result was observed in …
Degradation of carotenoids in orange juice during microwave heating
2010
Degradation of carotenoids in orange juice was monitored during microwave (MW) heating at different time/temperature conditions. Various carotenoids were identified and quantified by HPLC. Degradation rate of carotenoids was influenced by MW heating temperatures: at 60 degrees C and 70 degrees C for 10 min violaxanthin and antheraxanthin were the compounds most unstable, while lutein and provitamin A carotenoids were more stable. At 85 degrees C a decrease of about 50% was observed for almost all carotenoids after 1 min of MW heating. Temperature sensitivity (z value) for total carotenoids was 14.2 degrees C, for single compounds z values ranged between 10.9 degrees C for beta-carotene and …
Carotenoid Profile Modification during Refrigerated Storage in Untreated and Pasteurized Orange Juice and Orange Juice Treated with High-Intensity Pu…
2006
A comparative study was made of the evolution and modification of various carotenoids and vitamin A in untreated orange juice, pasteurized orange juice (90 degrees C, 20 s), and orange juice processed with high-intensity pulsed electric fields (HIPEF) (30 kV/cm, 100 micros), during 7 weeks of storage at 2 and 10 degrees C. The concentration of total carotenoids in the untreated juice decreased by 12.6% when the juice was pasteurized, whereas the decrease was only 6.7% when the juice was treated with HIPEF. Vitamin A was greatest in the untreated orange juice, followed by orange juice treated with HIPEF (decrease of 7.52%) and, last, pasteurized orange juice (decrease of 15.62%). The decreas…
Changes of colour and carotenoids contents during high intensity pulsed electric field treatment in orange juices
2005
Abstract Liquid chromatography (LC) was the method chosen to evaluate the effects of high intensity pulsed electric fields (HIPEF), with different electric field intensities (25, 30, 35 and 40 kV/cm) and different treatment times (30–340 μs), on orange juice cis / trans carotenoid contents. In parallel, a conventional heat treatment (90 °C, 20 s) was applied to the orange juice in order to compare the effect on the carotenoid contents. HIPEF processing of orange juice is an alternative to the thermal treatment of pasteurization, provided that it is kept refrigerated, because, when the most extreme conditions of this kind of treatment are applied, the decrease in the concentration of caroten…
Erosive effect of industrialized fruit juices exposure in enamel and dentine substrates: An in vitro study
2021
Background Erosive tooth wear has been a highly prevalent and emerging phenomenon related to eating habits of the population. Aim: This study sought to investigate industrialized fruit juices exposure in enamel and dentine substrates in terms of erosive effect. Material and methods Human enamel and dentine specimens were randomized into 8 groups (n=8): Grape juice - Ades®, Grape juice - Del Valle Kapo®, Grape juice - Aurora®, Orange juice - Del Valle Kapo®, Orange juice - Ades®, Strawberry juice - Mais Vita®, Strawberry juice - Ades®, Citrus fruit juice - Tampico®. Specimens were submitted to an in vitro erosive challenge and to a microhardness test to evaluate the percentage of surface mic…
Inactivation kinetics of pectin methyl esterase under combined thermal–high pressure treatment in an orange juice–milk beverage
2008
Abstract The inactivation kinetics of PME in an orange juice–milk beverage system treated by thermal (65–80 °C) and combined thermal (25–65 °C)–high pressure (0.1–700 MPa) processes were fitted using a biphasic model. About 6–8% of the initial activity corresponding to the heat and pressure stable fraction was observed. For complete inactivation a treatment at 90 °C, 1 min or 700 MPa at 55 °C for 2 min was necessary showing the protective effect of the orange–milk media. The extent of inactivation was different in the orange matrices showing that PME was more thermostable in the orange juice–milk based beverage system as compared to the purified enzyme in a buffer system. On the other hand,…