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1.
Rice milling operation is a very energy-intensive process. The major qualities of the rice which are taken into consideration
while milling are the degree of milling and head rice yield. A laboratory abrasion polisher, modified by attaching a humidifying
and cooling unit, was used to polish long-grain Pusa Basmati rice in order to optimize the polishing conditions. Polishing experiments were carried out using central composite design
for a factorial with a central point, at different initial grain temperatures (5–25 °C) and milling chamber temperatures (11–25 °C)
at a constant humidity level of 95 ± 2% for different time intervals. Models capable of predicting the quality of milled rice
were developed using response surface methodology and used to determine optimum processing conditions. Responses such as degree
of milling (DOM), broken content, and specific energy consumption were used to assess product quality. Optimum milling conditions
of a minimum of 10% DOM, a broken content of 8%, and a specific energy consumption of 11 kJ/DOM were obtained at a milling
chamber temperature of 11 °C, an initial grain temperature of 15 °C, and a milling period of 180 s. 相似文献
2.
Jose Vicente Garcia-Perez Carmen Ortuño Ana Puig Juan A. Carcel Isabel Perez-Munuera 《Food and Bioprocess Technology》2012,5(6):2256-2265
The main aim of this work was to evaluate the effect of high-intensity ultrasound (US) on the drying kinetics of orange peel as well as its influence on the microstructural changes induced during drying. Convective drying kinetics of orange peel slabs were carried out at a relative humidity of 26.5 ± 0.9%, 40 °C and 1 m/s with (AIR+US) and without (AIR) ultrasound application. In order to identify the US effect on water transport, drying kinetics were analyzed by taking the diffusion theory into account. Fresh, AIR and AIR+US dried samples were analyzed using Cryo-Scanning Electron Microscopy. Results showed that the drying kinetics of orange peel were significantly improved by US application, which involved a significant (p < 0.05) improvement of mass transfer coefficient and effective moisture diffusivity. The effects on mass transfer properties were confirmed with microstructural observations. In the cuticle surface of flavedo, the pores were obstructed by the spread of the waxy components, this fact evidencing US effects on the air–solid interfaces. Furthermore, the cells of the albedo were disrupted by US, as it created large intercellular air spaces facilitating water transfer through the tissue. 相似文献
3.
Thin Layer Drying of African Breadfruit (Treculia africana) Seeds: Modeling and Rehydration Capacity
African breadfruit (ABF) seeds are underutilized plant resources, which have been reported to have high potential for novel
food and industrial uses. The kinetics of moisture removal during air drying of the whole (WS) and dehulled (DS) seeds was
studied at temperatures of 40–70 °C. Five empirical models were tested for predicting the experimental data. Drying of ABF
seeds followed an exponential decay pattern, while drying predominantly took place during the falling rate periods. All the
drying models predicted the experimental data above 90% accuracy while the Henderson–Pabis model gave the best fit (0.95 < r
2 < 0.99) at most of the experimental conditions. Effective moisture diffusivity, D
eff, ranged from 3.65 to 7.15 × 10−9 m2/s and 3.95 to 6.10 × 10−9 m2/s for WS and DS, respectively. D
eff showed significant dependence on the moisture content (p < 0.01). Rehydration capacity of DS was not significantly affected by drying temperature while that of WS increased with
drying temperature. 相似文献
4.
Laira P. Fraga Patrícia O. Carvalho Gabriela A. Macedo 《Food and Bioprocess Technology》2012,5(1):138-146
The production of cutinase by solid-state fermentation, using by-products such as wheat bran, rice bran, or soybean rind,
was carried out using a Fusarium oxysporum strain. The fermentation process was optimized using a central composite design. The best conditions for cutinase production
were achieved at 28–30 °C, with water added at 100–150% (w/w) after 72 h of incubation, in the range of 11.7–15.5 U/mL. In addition, the resolution of (R,S)-2-octanol and (R,S)-ibuprofen was performed to evaluate the enantioselectivity of the preparations of cutinase. The cutinase produced from the
soybean rind attained higher yields and enantioselectivity in the resolution of (R,S)-2-octanol with octanoic acid in isooctane (E = 9.6). For the (R,S)-ibuprofen resolution, the cutinase produced from rice bran reached the best yields (E = 5.6). This work demonstrated that the enzymes can be produced from different media, such as from by-products or residues
rich in carbon sources that do not necessarily present the same biochemical properties, which may be useful for industrial
applications. 相似文献
5.
Markus Zell James G. Lyng Desmond J. Morgan Denis A. Cronin 《Food and Bioprocess Technology》2012,5(1):265-272
Selected parameters (cooking loss, instrumental colour and texture and sensory quality) of a brine-injected pork muscle cooked
by a novel and rapid ohmic cooking protocol were examined and compared with those obtained in conventionally cooked samples.
Ohmic samples were cooked using either a low-temperature long-time (LTLT) protocol (2 min equilibration, 5 min ohmic heating
to 70 °C, 8 min holding) or a high-temperature short-time (HTST) procedure (2 min equilibration, 6 min ohmic heating to 95 °C)
performed within a hot air cabinet set at 80 °C (LTLT) and 100 °C (HTST). Conventional cooking (steam oven at 80 °C for 120 min)
was conducted to a core temperature of 70 °C. The LTLT treatment gave a much lower cooking loss value (4–5% lower, p < 0.05) than the other treatments, though the full magnitude of this difference was not completely reflected in the proximate
composition of the cooked products. Ohmically cooked ham showed a significantly (p < 0.05) lighter surface colour with Hunter L values of 65.3 (LTLT) and 63.5 (HTST) relative to the control (61.4). Texture
profile analysis (TPA) indicated a significant difference (p < 0.05) in hardness (N) especially between the HTST surface (82.1 N) and the conventional centre (58.8 N). Although the ohmic
cooking protocols yielded products with quite acceptable eating qualities, sensory evaluation found the overall quality of
the conventionally cooked ham to be significantly (p < 0.05) superior, indicating that further optimisation of the ohmic cooking protocols would be required prior to any commercial
adoption. 相似文献
6.
Various physical, chemical, and mechanical properties of three indica varieties of rice were investigated. The rice varieties were categorized into extra long-and-slender, medium, and short-and-bold types, based on their length and slenderness ratio, with amylose contents 16.7, 22.6, and 26.4%, for ADT37, Swarna, and Pusa Basmati, respectively. Brown rice samples were milled to different degrees, and various mechanical properties like wear index and milling coefficient were devised to characterize the rice quality. Wear index, which is the indicator of polishing behavior, was found to vary 0.1–0.02 g/min for 2–18% degree of milling. Milling coefficient, an indicator of surface area requirement for different varieties of rice, was found to be higher for long-and-slender type of rice. 相似文献
7.
Effect of heat treatment on colour stability of dried salak fruit during storage was investigated by using hot air (40–90 °C), heat pump (isothermal and intermittent modes, 26–37 °C) and freeze-drying. Influence of pre-treatment on the colour property was studied as well by blanching the sample at three levels of temperature (50–70 °C). Total colour change (∆E*) was used to assess the colour degradation kinetics and quantify the degree of browning during processing and storage. It was found that the dried pre-treated sample under heat pump isothermal drying recorded the highest ∆E* value during storage followed by non-pre-treated samples under heat pump intermittent drying, freeze-drying, hot air-drying and heat pump isothermal drying. Weibull model is found to better fit the experimental data as compared with zero-order and first-order kinetics models. Analysis on the kinetics constants reveals that the heat treatment could affect the microstructure, water sorption properties and concentration of reacting species of the dried product. This in turn contributes to the colour changes of the dried product during storage. 相似文献
8.
Indrajit D. Thorat Debabandya Mohapatra R. F. Sutar S. S. Kapdi Dipali D. Jagtap 《Food and Bioprocess Technology》2012,5(4):1379-1383
The vacuum-drying characteristics of ginger (Zingiber officinale R.) slices were investigated. Drying experiments were carried out at a constant chamber pressure of 8 kPa, and at four different
drying temperatures (40 °C, 50 °C, 60 °C, and 65 °C).The effects of drying temperature on the drying rate and moisture ratio
of the ginger samples were evaluated. Efficient model for describing the vacuum-drying process was chosen by fitting five
commonly used drying models and a suggested polynomial was fitted to the experimental data. The effective moisture diffusivity
and activation energy were calculated using an infinite series solution of Fick’s diffusion equation. The results showed that
increasing drying temperature accelerated the vacuum-drying process. All drying experiments had only falling rate period.
The goodness of fit tests indicated that the proposed two-term exponential model gave the best fit to experimental results
among the five tested drying models. The average effective diffusivity values varied from 1.859 × 10−8 to 4.777 × 10−8 m2/s over the temperature range. The temperature dependence of the effective moisture diffusivity for the vacuum drying of the
ginger samples was satisfactorily described by an Arrhenius-type relationship with activation energy value of 35.675 kJ/mol
within 40–65 °C temperature range. 相似文献
9.
Teresa De Pilli Roma Giuliani Antonio Derossi Carla Severini 《Journal of food engineering》2009,95(3):453-459
The aim of this work is to evaluate and compare the effects of microwave and conventional drying (hot air) on the quality characteristics of cooked pasta. Experiments were carried out on pasta type spaghetti.A huge difference was noticed between times necessary to dry samples by hot air and by microwaves, in fact in the first case, the drying time was on the average 204.5 min vs. 61.7 s of microwave treatment (average). The gelatinization degree of samples dried by hot air was faster than that of those dried by microwaves: the medium values of kinetic constant of gelatinization of samples dried by hot air and microwaves were 7.5 and 5.2, respectively. Similar total organic matter values suggest that the cooking quality of samples differently dried was comparable. Moreover, samples dried by microwaves were thicker than pasta dried by hot air (37.8 vs. 27.4). 相似文献
10.
The kinetics of colour and carotenoids degradation in jackfruit bulb slices was evaluated during hot air drying at 50, 60
and 70 °C. Visual colour as well as total carotenoids (TC) content was found to be influenced by the drying process. Tri-stimulus
colour parameters such as Hunter L and b values decreased and a value increased during drying. The combination of Hunter L × b value was found to represent the colour change adequately. Degradation of TC and visual colour in terms of Hunter L × b value followed first-order reaction kinetics; however, zero-order reaction kinetics was found adequate to describe changes
in total colour difference (TCD) and non-enzymatic browning (NEB). Dependence of the rate constant followed the Arrhenius
relationship. The process activation energies (E
a) for Hunter L × b value, TCD, NEB and TC were 29.96, 27.21, 27.48 and 55.61 kJ/mol, respectively. Higher E
a for TC content indicated greater temperature sensitivity as compared with other colour parameters. Relationship of TC content
and Hunter L × b value was found to be more consistent through regression analysis with R
2 ≥ 0.979. 相似文献
11.
Effect of different moisture equilibration process on the quality of apple chips dried by instant controlled pressure drop (dic)‐assisted hot air drying
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Moisture equilibration process (MEP) is an important process before controlled pressure drop (DIC) drying to obtain greater products quality and avoid producing bubbles. The aim of this work was to study the effect of MEP on the quality of apple chips dried by instant controlled pressure drop‐assisted hot air drying (DIC‐AD). After predrying by AD, four types of moisture equilibration solutions were applied to equilibrate the moisture of apple chips before DIC. The quality of apple chips equilibrated in water for 10 min was superior to those for 30 and 60 min with better color, brittleness, hardness, puffing degree (PD), and microstructure. Sugar solutions showed positive effect on brittleness and hardness, PD, and soluble solids of apple chips. In addition, calcium chloride was beneficial to the color of apple chips, and the product showed good rehydration and PD possibly due to the reaction between pectin and calcium ions.
Practical applications
Instant controlled pressure drop (DIC) was a new sort of united drying method that can combine with other drying technology, such as hot air drying and freezing drying. In practical production, apple slices are usually dried to low moisture content for long time storage and regained appropriate moisture content before drying. After predrying, moisture equilibration process (MEP) is an important process before DIC drying which made water homogenous distributed in the sample to obtain greater products quality and avoid producing bubbles during DIC drying. In this study, MEP with different solutions including water, fructose syrup, maltitol, and calcium chloride were performed before DIC drying, and the changes of physiochemical properties of dried products were studied. Based on the analysis of experimental results, predried apple slice equilibrated in water for 10 min, 10% fructose syrup and 30% maltitol solution might produce apple chips with better quality. 相似文献12.
Effects of freezing/thawing, sun drying, solar drying, and foam-mat drying on physical, chemical, rheological, and sensory
attributes of okra were investigated. Average poured bulk and tapped bulk densities of sun-dried, solar-dried, and foam-mat-dried
okra were 800 and 950, 715 and 765, 355 and 367 kg/m3, respectively. Minimum and maximum porosity of sun-dried, solar-dried, and foam-mat dried okra were 55.70% and 62.60%, 50.06%
and 53.30%, 60.90% and 62.87%, respectively. Sun-dried and solar-dried okra showed higher L*, a*, and chroma values than frozen/thawed and foam-mat-dried okra. Within a temperature range of 80–40 °C, viscosity of fresh,
frozen/thawed, foam-mat-dried, solar-dried, and sun-dried okra were 0.055–0.080, 0.055–0.075, 0.050–0.073, 0.005–0.065, and
0.005–0.022 Nsm−2, respectively. Sensory evaluation showed no significant difference (p < 0.05) between fresh, frozen/thawed, and foam-mat dried okra in color, aroma, and overall acceptability. Sun-dried and solar-dried
okra were significantly poorer (p < 0.05) in color, aroma, taste, and overall acceptability. 相似文献
13.
Mahboube Zolfaghari Mohammad Ali Sahari Mohsen Barzegar Hamidreza Samadloiy 《Food and Bioprocess Technology》2010,3(2):239-246
Samples of Abbot, Alison, Bruno, Monty, and Hayward cultivars of kiwifruit (Actinidia deliciosa) were obtained from the Iran Research Center of Citrus (Tonekabon, located in north of Iran) and their physicochemical properties
were studied during cold storage (at T = 1 ± 1 °C, RH = 80 ± 5%) at 0-, 9-, and 18-week intervals. The mean chemical composition of the fruits were as follows:
ash = 0.66–0.96%, moisture = 75.2–84.7%, starch = 0.3–7.0%, and ascorbic acid = 54.8–261.0; K = 125.0–372.0 mg 100 g−1 fresh weight, Mg = 18.0–32.0 mg 100 g−1 fresh weight, Na = 1.4–3.1 mg 100 g−1 fresh weight, Fe = 0.17–0.52 mg 100 g−1 fresh weight, Cu = 0.04–0.24 mg 100 g−1 fresh weight, Zn = 0.16–0.49 mg 100 g−1 fresh weight, Mn = 0.04–0.10 mg 100 g−1 fresh weight, and P = 25.2–49.3 mg 100 g−1 fresh weight; glucose = 0.7–2.39%, fructose = 1.20–3.13%, and sucrose = 0.0–5.8%. At the same time, the values of the parameters
°Brix = 6.5–14.8% and acidity = 1.8–2.5% of the studied cultivars (mutual effects of cultivar and storage time) were investigated.
The increase in peroxidase (POX = 0.0–6.65 U ml−1) and the decrease in pectinesterase (PE; poor activity to 0) activities were also determined. The statistical analysis showed
that the Bruno cultivar had the highest content of ascorbic acid (115.0–261.0 mg 100 g−1 fresh weight), which is an important compound in fruits during storage, while Hayward had the best overall quality particularly
with regards to its resistance to softening. This study confirms that long-term cold storage at 1 ± 1 °C and 80 ± 5% RH is
suitable for maintaining the highest quality of Iranian grown cultivars of kiwifruit. 相似文献
14.
Brahim Bchir Souhail Besbes Romdhane Karoui Hamadi Attia Michel Paquot Christophe Blecker 《Food and Bioprocess Technology》2012,5(5):1840-1852
The drying of pomegranate seeds was investigated at 40 °C, 50 °C and 60 °C with air velocity of 2 m/s. Prior to drying, seeds
were osmodehydrated in 55 °Brix sucrose solution for 20 min at 50 °C. The drying kinetics and the effects of osmotic dehydration
(OD) and air-drying temperature on antioxidant capacity, total phenolics, colour and texture were determined. Analysis of
variance revealed that OD and air-drying temperature have a significant influence on the quality of seeds. Both anthocyanin
and total phenolic contents decreased when air-drying temperature increased. The radical diphenylpicril-hydrazyl activity
showed the lowest antioxidant activity at 60 °C. Both chromatic parameters (L*, C* and h°) and browning index were affected by drying temperatures, which contributed to the discolouring of seeds. The final product
has 22%, 20% and 16% of moisture; 0.630, 0.478 and 0.414 of a
w; 151, 141 and 134 mg gallic acid equivalent/100 g fresh matter (FM) of total phenolics; 40, 24, 20 mg/100 g FM of anthocyanins
and 46%, 39% and 31% of antioxidant activity, for drying temperatures of 40 °C, 50 °C and 60 °C, respectively. In view of
these results, the temperature of 40 °C is recommended as it has the lowest impact on the quality parameters of the seeds.
Differential scanning calorimetry data provided complementary information on the mobility changes of water during drying.
Glass transition temperature (Tg′) depends on moisture content and as consequence, on drying conditions. In fact, Tg′ of seeds
dried at 60 °C (Tg′ = −21 °C) was higher than those dried at 50 °C (Tg′ = −28 °C) or 40 °C (Tg′ = −31 °C) and osmodehydrated
seeds (Tg′ = −34 °C). During OD and drying process, the texture of seeds changed. The thickness of seeds shrank by 55% at
60 °C. 相似文献
15.
Mass Transfer Coefficients for the Drying of Pumpkin (Cucurbita moschata) and Dried Product Quality 总被引:3,自引:0,他引:3
Raquel Pinho F. Guiné Francisca Henrriques Maria Jo?o Barroca 《Food and Bioprocess Technology》2012,5(1):176-183
The aim of this work was to determine the mass transfer properties of pumpkin (Cucurbita moschata) exposed to air drying. The drying temperatures tested ranged between 30°C and 70°C, and the kinetic behavior was studied
in this temperature band. The samples were analyzed in terms of moisture content, acidity, proteins, lipids, and crude fiber,
both in the fresh state and after drying. From the chemical analyses made, it was possible to conclude that drying induces
some reductions in acidity, lipids, fibers, and proteins. As to the influence of the drying temperature on the process, it
was observed that a temperature rise from 30°C to 70°C led to a 70% saving in drying time. The results obtained by fitting
the experimental data to the kinetic models tested allowed concluding that the best model for the present case is Henderson–Pabis,
and the worst is Vega–Lemus. Furthermore, in this work, it was possible to determine the values of the diffusion coefficient
at an infinite temperature, D
e0, and activation energy for moisture diffusion, E
d, which were, respectively, 0.0039 m2/s and 32.26 kJ/mol. Similarly, the values of the Arrhenius constant and the activation energy for convective mass transfer,
respectively, h
m0 and E
c, were also calculated, the first being 3.798 × 108 m/s and the latter 86.25 kJ/mol. These results indicate that the activation energy for convective mass transfer is higher
than that for mass diffusion. 相似文献
16.
Adebisola J. Aina Kolawole O. Falade John O. Akingbala Pathelene Titus 《Food and Bioprocess Technology》2012,5(2):576-583
The proximate compositions and physicochemical properties of 21 Caribbean sweet potato (Ipomoea batatas (L) Lam) starches were investigated. Proximate composition, amylose, reducing and non-reducing sugars were determined using
standard methods. Swelling power and solubility were evaluated and pasting properties of the starches were determined using
Rapid Visco Analyzer. Moisture (8.0–12.4%), protein (0.0–0.2%), ash (0.1–0.5%), and reducing (0.3–2.3%) and non-reducing sugar
(0.1–0.2%) contents of starches were significantly different (P < 0.05) among the cultivars. Amylose content varied significantly between 12.8–21.3%. Swelling power and solubility ranged
between 7.8–31.1% and 1.5–9.6%, respectively. Pasting properties such as peak viscosity measured in Rapid Visco Units (143.2–288.8 RVU),
breakdown viscosity (29.4–162.6 RVU), and setback viscosity (15.0–78.8 RVU), pasting temperature (73.5–87.7 °C) and time to
pasting temperature (3.6–4.5 min) varied significantly among the cultivars. Breakdown viscosity was poorly correlated with
final viscosity attained (r = − 0.0507, P < 0.05); however, pasting temperature was correlated (r = 0.479, P < 0.05) with setback viscosity. The variability observed in the physicochemical properties of the starches was related to
specific requirements for use in the production of noodles, pasta, and inclusion in bread and weaning food formulations. 相似文献
17.
Evangelina Leiva Díaz Leda Giannuzzi Sergio A. Giner 《Food and Bioprocess Technology》2009,2(2):194-207
A novel, flexible sheet-like food formed by the high methoxyl pectin–sugar–acid gelation during drying of apple puree was
investigated to characterize drying-related properties. Product volume was reduced by 68% over the process, and this shrinkage
was successfully modeled by assuming the volume reduction equal to the volume of water evaporated. The sorption isotherm at
25 °C was determined, and a new expression for the moisture content, W, as a function of water activity, a
w, of the type resulted as the most accurate for this J-shaped isotherm. The drying kinetics was studied at 50, 60, and 80 °C in a tray
dryer. No constant drying rate period was found, and the drying curve was divided in high- and low-moisture zones. For high
moistures, an internal–external mixed control diffusive model coupling mass and heat transfer was applied to obtain a mass
transfer Biot number of 2.1. In the low-moisture zone, a diffusive, isothermal drying model for strict internal control was
utilized. Diffusivities varied around 1 × 10–9 m2/s for high moistures and were about ten times lower at low moistures, although the activation energies were comparable (15,259
and 16,800 J/mol, respectively). The drying time at 60 °C was 6.67 h. The product scored four points out of five in a sensory
evaluation of general acceptability. 相似文献
18.
Caglar Ozdemir Ozlet Akca E. Ilker Medine Dilek Odaci Demirkol Perihan Unak Suna Timur 《Food Analytical Methods》2012,5(4):731-736
Fe3O4 magnetic nanoparticles (MNPs) were synthesized and silanized to form a core–shell (Fe3O4–SiO2) structure. Afterwards, surface modification with amino silane was carried out to produce amino groups on the MNPs for the
biomolecule immobilization. In order to test the performance of amino functional MNPs as immobilization platform in biosensing
applications, glucose oxidase was immobilized on the surface via glutaraldehyde. Obtained Bio-MNPs were then fixed onto the
carbon paste electrode by the aid of magnetic force and used as the working electrode during the amperometric measurements
at −0.7 V versus Ag/AgCl. After optimization of some parameters affecting the biosensor performance, analytical characterization
was carried out. Linearity was found in the range of 0.25–2.0 mM glucose and defined by the equation of y = 8.366x + 1.819, (R
2 = 0.996). Proposed biosensor was then applied for the glucose analysis in various beverages. Finally, data were compared
with a commercial enzyme assay kit based on spectrophotometric Trinder reaction as a reference method. 相似文献
19.
Jessica López Elsa Uribe Antonio Vega-Gálvez Margarita Miranda Judith Vergara Eduardo Gonzalez Karina Di Scala 《Food and Bioprocess Technology》2010,3(5):772-777
Effect of air temperature on drying kinetics, vitamin C, antioxidant capacity, total phenolic content (TPC), colour due to
non-enzymatic browning (NEB) and firmness during drying of blueberries was studied. Drying curves were satisfactorily simulated
with the Weibull model at 50, 60, 70, 80 and 90°C. The scale parameter (β) decreased as air temperature increased and an activation
energy value of 57.85 kJ mol−1 was found. Important losses of vitamin C were reported during drying for all the working temperatures (p < 0.05). Although TPC decreased as air-drying temperature increased (p < 0.05) in comparison to its initial value, the dehydration at high temperatures (e.g., 90°C) presented high values for these
antioxidant components. Discoloration due to NEB reaction was observed at all the working temperatures showing a maximum value
at 90°C (p < 0.05). The radical scavenging activity showed higher antioxidant activity at high temperatures (80 and 90°C) than at low
temperatures (50, 60 and 70°C) (p < 0.05). A tissue firmness reduction was observed with increasing temperature (p < 0.05). 相似文献
20.
Donatella Albanese Giuseppina Adiletta Mariantonietta D′Acunto Luciano Cinquanta Marisa Di Matteo 《International Journal of Food Science & Technology》2014,49(11):2458-2463
Tomato peels were firstly dried by different methods (hot air, freeze‐drying, and fluidized bed drying) to evaluate the recovery of lycopene, β‐carotene and DPPH radical scavenging activity. Comparison of the results showed that hot air drying at 50 °C was a suitable method and alternative to freeze‐drying to preserve carotenoids compounds and antioxidant activity in tomato peels. Then, ethanol/ethyl acetate (1:1) extracts from tomato peel, previously dried at 50 °C by hot air, were submitted to heat (100 °C) and light treatment (1000 lumen) to evaluate their stability as natural food dyes. Heating of the extracts caused a progressive reduction of total carotenoids, up to about 30% after 250 min of treatment, whereas the colour at the end of heat treatment showed small changes, with an overall colour difference (?E) equal to 7. Fluorescent lighting treatment showed an almost total degradation of carotenoids in the extracts after 48 h combined with a fading colour. 相似文献