Total Pigment Content Research Articles

The influence of goat genotype on the production of Capretto and Chevon carcasses. 2. Meat quality

The effect of five goat genotypes, Boer×Angora (BA), Boer×Saanen (BS), Feral×Feral (FF), Saanen x Angora (SA) and Saanen x Feral (SF) on the meat quality of Capretto and Chevon carcasses obtained from 50 buck kids, was assessed. Genotype had an influence on cooking loss and longissimus thoracis muscle colour coordinates (CIE L *, a *, b * values). BS kids from the Capretto group had paler muscle colour compared to other genotypes; pale muscle colour being required for Capretto carcasses. Total pigment concentration, fat colour, shear force values and sensory scores for flavour, tenderness, juiciness and overall acceptability did not differ significantly between genotypes. Muscle colour became darker and fat colour became more yellow with increasing animal age. Tenderness decreased with animal age as indicated by higher shear force values. Age had no significant influence on cooking loss and sensory scores.

The Atmospheric Effect Correction of the Ocean Color Imager of ROCSAT-1-Simulations and Using SeaWiFS Data as the Example

The total radiance observed by satellite-borne ocean color sensors results from several contributions: the atmospheric molecular and aerosol scattering, the sea surface reflectance and the water leaving radiance. In order to apply these ocean color sensor data to access the ocean parameters, atmospheric correction should be undertaken in advance to extract the water leaving radiance that is relevant to the ocean parameters. The aim of this study is to establish one atmospheric correction process for the Ocean Color Imager (OCI) of ROCSAT-1, and some pre-launch simulation results are demonstrated. The simulation shows that the water leaving radiance estimation seems to be reliable by the ocean color radiance algorithm proposed in this paper, because the estimated total pigment concentration seems to be reasonable. Further investigations done in this study using SeaWiFS data reveal that the water leaving radiance is somewhat overestimated in comparison with ship measurements because of the underestimated aerosol scattering. The reason for this underestimation is probably the inconsistent marine aerosol type and size distribution between the real and input atmospheric parameters. The simulated result also shows the sun glint effect is significant and plays the most important role in the radiance contributions of OCI imagery. Consequently, choosing the most suitable acquiring time of OCI in order to avoid the sun glint effect will be very important in future OCI operation scheduling.

Tolerance to atmospheric ozone in transgenic tobacco over‐expressing glutathione synthetase in plastids

A cross between transgenic tobacco (Nicotiana tabacum L.) plants which over‐expressed either γ‐glutamylcysteine synthetase (cpGSHI) or glutathione synthetase (cpGSHII) in their chloroplasts was used to compare the consequences of over‐expression of components of the glutathione synthetic pathway on tolerance to atmospheric O3 or paraquat. A high proportion (50%) of those progeny which carried the cpGSHII transgene alone showed tolerance to atmospheric O3 but not to paraquat. Progeny of an additional two, independent, self‐pollinated primary transgenic lines, which segregated in a Mendelian fashion for the presence of the cpGSHII transgene and therefore included both transformed and non‐transformed (recessive, wild‐type) plants, were also challenged by fumigation with O3. Again, in both cases, about 50% of the plants expressing the epGSHII transgene were found to be O3‐tolerant on the basis of reduced ethylene emissions and increased or unchanged total pigment concentrations. However, this tolerance was not due to specific changes in stomatal densities.

Meat Color and Biochemical Characteristics of Unacceptable Dark‐colored Broiler Chicken Carcasses

ABSTRACTSpectrocolorimetry, pH, TBARS, total pigment and myoglobin were measured in normal and abnormally dark‐colored broiler chicken breast muscle. Analyses of L*, a* and b* values revealed that a* values were highly sensitive and specific to differentiate normal from dark‐colored carcasses and thus could be used as a potential diagnostic method for carcass classification at slaughter. Color characteristics (L*, a*, and b* values), pH, total pigment, myoglobin, and iron concentrations were all significantly different in dark‐colored muscle when compared with normal muscle. TBARS values and percentage moisture for the two groups were not different.

Colour differences in paprika pepper varieties (Capsicum annuumL) cultivated in a greenhouse and in the open air

The quality of six paprika pepper varieties, cultivated in a greenhouse and in the open air, has been studied. There were differences in their paprika colours with regard to the total content of pigments (ASTA unities) and the quotient of the absorbance spectra values for red and yellow pigments (tint). Using colorimetric measurements, directly carried out on the surface of the ripe fruits, the varieties are clearly separated in the CIELAB space colour, depending on their growing conditions. The colorimetric coordinates a * and b * and quotient a * /b * of the ripe fruits, cultivated in greenhouse, allow to predict the total pigments concentration of the resulting paprika. For the cultivations in the open air, the fruit brightness (L * ) and the chromatic quotient 2000 x a * /L * x b * are the parameters which show best the correlation with the total content of the paprika pigments. The fruit colour change, from green to red, coincides in both growing conditions with the moment when the chlorophyll b concentration surpasses the a one.

Lutein and lutein ester content in different types of Tagetes patula and T. erecta

Lutein and lutein fatty acid ester content in two different parts (petals and calyces) of flower-heads from different types of marigold belonging to the species Tagetes patula and T. erecta were evaluated by HPLC combined with a diode array detector (DAD). A typical chromatographic profile of pigments was characterized by the simultaneous presence of lutein and eight lutein esters. Relevant quantitative differences were found among the marigold types which had a total content of pigments ranging from 17 to 570 mg/100 g in the petals and from 0.4 to 18.6 mg/100 g in the calyces. The petal colours were also defined by the L*, a* and b* values determined by a chroma meter. Differences in petal colour were well related to the pigment content and good correlations between pigment concentration and L* and a* values were found.

Comparison of different fluorometers (PAM, 1- Hz, BackScat and Turner) measuring either chlorophyll concentration or photosynthetic activity

Like other commercial fluorometers the 1-Hz fluorometer is a device that can measure chlorophyll-α concentrations even in highly diluted phytoplankton suspensions. In contrast to those fluorometers, it measures rates of photosynthetic activity in relation to the total amount of detectable fluorescent material. Applications include the determination of total algal pigment concentrations as well as algal productivity. In this work the primary production was detected by fluorescence yield measurements at different irradiances. Fluorometrically analysed rates were correlated with the carbon fixation rate measured by14C incubation. Fluorescence data were sampled in parallel experiments by thePAM (pulse amplitude modulated)-and 1-Hz fluorometer. The results of the14C incubation method were highly correlated with the calculated 1-Hz — andPAM fluorometer data. The applications presented show that it is possible with both fluorometers to measure the impact of environmental changes on the production of phytoplankton communitiesin vivo.

Transepithelial fate of bilirubin in the isolated rat kidney

The renal handling of bilirubin in the rat was studied using an isolated kidney preparation by means of the determination of total pigment concentration decay in the perfusion medium and its renal clearance. Unconjugated bilirubin was incorporated in the perfusate at a concentration of about 4 μg/ml. In order to establish the potential role of secretion in renal handling of the pigment, experiments were also performed incorporating in the perfusate different doses of nicotinic acid (NA) (0.1 and 1.0 mM final concentration), which is considered an alternative substrate for the organic anion transport system, or probenecid (Prob) (0.1 and 1.0 mM final concentration), the classical inhibitor of organic anion transport process. The magnitude of pigment uptake from the perfusion medium, estimated by a first order exponential decay constant, was decreased in a dose-dependent way by NA (40 and 76% decrease for 0.1 and 1.0 mM of NA, respectively) and Prob (57 and 88% decrease for 0.1 and 1.0 mM of Prob, respectively). NA and Prob also induced a diminution in the ratio of pigment renal clearance to glomerular filtration rate (24 and 48% decrease for 0.1 and 1.0 mM of NA and 52 and 55% decrease for 0.1 and 1.0 mM of Prob). Based on these findings, it can be proposed that tubular secretion through the proximal cells contributes significantly to renal pigment depuration. In order to establish the possible contribution of cellular metabolism to the secretory process, a different set of experiments was conducted. The content of bilirubin mono and diconjugates (BMC and BDC) were determined in urine, in arterial and venous samples and in renal cortex. Studies performed using either an open or a closed circulating system, revealed that after conjugation in the renal cell, pigment derivatives can be secreted into both the tubule and the venous compartments. Total bilirubin concentration as well as the relative content of BMC and BDC in urine increased over time, representing the sum of both conjugates about 50% of the total pigment excreted by the end of experiments. Consequently, our results support the existence of a tubular transepithelial transport of bilirubin, playing the metabolism of the pigment an important role in this process.

Effects of high natural seston concentrations on the feeding, selection, and absorption of the oyster Crassostrea gigas (Thunberg)

Feeding, selection and absorption were determined for the Pacific oyster Crassostrea gigas cultivated in the Bay of Marennes-Oléron, over a spring/neap tidal cycle. Physiological determinations were related to the highly variable food environment with continuous recordings of turbidity and fluorescence. In this bay, resuspension processes have a major influence on food availability and quality. Seston characteristics experienced by oysters can be summarized by high turbidity levels from 20 to 350 mg·l −1 and a predominance of the detritic fraction among the organic fraction (mean C/N ratio=16.57). Food is diluted by the fine resuspended sediment, and organic content of particulate matter in the water column decreases from 30% to 10% with increasing seston loads. Significant differences (Ancova, P<0.01), due to low retention efficiencies of the smaller particle size range, were recorded between the food quality (estimated by the organic content and the total pigment content) measured in the water column and the fraction retained by the oyster's gill. Below seston concentrations of 90 mg·l −1 ingestion rate was regulated by pseudofaecal production. Above 90 mg·l −1, a sharp reduction of filtration and rejection rates suggests physical constraints limiting food acquisition. The oyster selectively rejects inorganic from organic particles, enriching the ingested fraction. Amongst the potentially nutritive particles, significantly fewer particles containing phytopigments were rejected relative to organic particles (non-linear regressions, P<0.001). The negative influence, through food dilution, of high seston loads on net absorption efficiency was determined. This efficiency decreases with decreasing organic ingested fraction. Scope for growth calculations confirm the negative influence of seston loads, but show, supported by field growth measurements, that resuspended organic particles play an important role in the oyster's nutrition.

Physiological reactions to a change in light regime in cultured Skeletonema costatum (Bacillariophyta): implications for estimation of phytoplankton biomass

The marine planktonic diatom Skeletonema costatum (Cleve) was grown in batch culture under a 12 h light: 12 h dark (LD) regime for several generations before the experiment. At Time 0, half of the culture was transferred to continuous light (CL). Particulate organic carbon (POC), nitrogen (PON), and photosynthetic pigments (measured by spectrophotometry and high performance liquid chromatography) were monitored for 7 to 9 days in the two cultures. Under CL, POC and PON production were always lower. In addition, we measured a much higher proportion of chlorophyll degradation products (as chlorophyllid a, phaeophytin a and phaeophorbid a (PrD)). These indicate different physiological conditions between the two cultures, as reflected also be the lower POC/PON and chlorophyll a/POC ratios. Under CL illumination cells appear stressed, probably due to the total quantity of light to which cells are exposed. In fact, a higher proportion of the two xanthophylls diadinoxanthin and diatoxanthin in the CL culture indicates a photoprotective reaction of the cells. In contrast with the LD culture, parameters measured were not significantly inter-correlated in the CL culture. The lack of correlation between chlorophyll a and POC in CL does not encourage the use of the chlorophyll a/POC ratio as a biomass estimator. On the opposite, the ratio of total pigment content to POC did not vary much as a function of the light condition of the culture, remaining near 0.040 in both light regimes. Although further observations are needed, this index seems to be a reliable indicator of phytoplankton carbon biomass.

Veal colour assessment with three wavelengths

A method to derive reflectance spectra and colour coordinates of meat by measurement of reflectance at only three wavelengths, 480, 570 and 620 nm has been developed, by treating the spectra of a meat sample as a linear combination of the spectra of the three major myoglobin derivatives (reduced myoglobin, oxymyoglobin and metmyoglobin). Applied to 300 samples of Semitendinosus and Longissimus dorsi veal muscles at different times post mortem (24 h to 9 d), colour differences ΔE ∗ between the derived spectra and the real ones were about 1.5 units. The total pigment content, with high correlation with the extraction method ( P < 0.02), and the relative proportions of the derivatives can also be estimated.

Chlorophyll and Carotenoid Composition in Virgin Olive Oils from Various Spanish Olive Varieties

A study of chlorophyll and carotenoid composition of nine single-variety virgin olive oils from the main Spanish producing regions has shown differences depending on variety and ripening degree of the fruits. Pheophytin awas the major pigment in all the oils studied (44–58% total pigments), followed by lutein (18–38%) and β-carotene (6–17%). The chlorophyll pigments group also included pheophytinband in some cases chlorophyllsaandb. The carotenoid fraction also included the xanthophylls neoxanthin, violaxanthin, luteoxanthin, antheraxanthin, mutatoxanthin and β-cryptoxanthin. The mean provitamin A activity of the oils was 260 μg kg−1 expressed as retinol equivalent.cis-α-Carotene (tentative), mono- and di-esterified xanthophylls and pheophorbideawere pigments exclusive to Arbequina variety, a fact that could be used as a chemo-taxonomic differentiator of the oils of this variety. The ratio between the chlorophyll fraction and the carotenoid fraction was maintained in most cases around 1, demonstrating that the green and yellow fractions were in balance, notwithstanding their greater or lesser total pigment content. The considerable range in the lutein/β-carotene ratio (between 1·3 and 5·1 depending on variety) makes this ratio a differentiator of single-variety oils. Despite the different sources of the oils, some general trends have been shown which suggest what chlorophyll and carotenoid pigments should be expected in an olive oil so as to include it within the denomination ‘virgin’.

IMPROVED GROWTH AND TOLERANCE OF COWPEA TO IRRIGATION WITH WASTE EFFLUENTS FROM FERTILIZER'S FACTORIES USING MYCORRHIZAL FUNGUS (Glomus Fasiculatum)

Effect of preinoculation of mycorrhizal fungus (Glomus fasiculatum) on growth and tolerance of cowpea plants irrigated with different concentrations of waste effluents from industrial fertilizers was studied. The results indicated that, the relative growth rate, dry weight, nodule formation, total pigment content as well as tolerance indices of mycorrhizal cowpea plants were significantly reduced by irrigation with different levels of polluted water. Mycorrhizal association was found not only to improve all above parameters but also aid in overcoming the detrimental growth effect of irrigated water pollution. The results also revealed that, macro- -and micro-element contents, (P, N, Na, Mg, Cu, Co, Zn and Fe) of cowpea plants grown on polluted soil were much higher than that of unpolluted one. Results emphasized that VA mycorrhizal symbiosis can increase metal tolerance of cowpea plants. The VA mycorrhizal symbiosis could accumulate the heavy metals Co, Zn, Fe in mycorrhizal plant root than that of mycorhizal plant shoot. The percentage of VA mycorrhizal infection showed marked reduction with raising the pollution level. Evidently from the results proved that mycorrhizal dependencies for plant dry mass decreased at 10 & 20% pollution level, but, it increased at higher pollution level (40%).

Biochemical and Color Characteristics of Skinless Boneless Pale Chicken Breast

Extreme paleness of skinless, boneless chicken breasts sampled from the packaging area of a commercial processing plant was investigated. Six hundred fillets were collected during 10 visits to the same processing plant and were classified as normal (n = 300) and pale (n = 300) according to visual assessment by the principal investigator. Color (spectrocolorimetry) and pH of each fillet were measured within 1 h following collection. Fillets were frozen in liquid nitrogen and pooled samples of pale and normal meat were later analyzed for thiobarbituric acid reactive substances (TBARS), percentage moisture, total pigment, myoglobin, and iron concentrations. Color characteristics (L, a, and b values), pH, total pigment, myoglobin, and iron concentrations were all found to be significantly different in pale meat when compared with normal chicken breast. The TBARS values and percentage moisture for the two groups were not different. Analyses of L, a, and b values revealed that the L characteristic was a good color indicator that can be used to distinguish normal from pale samples, with both high sensitivity and high specificity. Moisture uptake in postchilled, pale fillets could not account for the decrease in total pigment concentration and myoglobin content.

Diel variations of gut fluorescence in the pontellid copepod Anomalocera patersoni

Abstract Diel variations in the gut fluorescence of Anomalocera patersoni (Copepoda, Pontellidae) were studied on adult males and females collected in the northwest Mediterranean at 1–2-hr intervals over a 24-hr cycle. Total pigment content (chlorophyll + phaeopigment) ranged from 5.1 to 19.5 ng ind.−1 in males and from 7.1 to 21.3 ng ind.−1 in females; it was higher at night than during the day in both sexes. As a result of the large dispersion of values, chlorophyll levels did not change significantly during the 24 hr cycle. Phaeopigment levels were highest at night between 19.45 and 23.45 GMT in both sexes. A smaller peak was noted around 12.30 GMT. Between these two peaks, lows were noted at 9.30 and 15.30 GMT, respectively. Thus, A. patersoni exhibits a diel bimodal rhythm in gut fluorescence. Individual phaeopigment levels were much lower than data reported for herbivorous species. These differences are certainly linked to the clearly carnivorous tendency of A. patersoni. In this species, the levels of phaeopigments seem to correspond to pigments contained in ingested prey. Rhythmic variations probably reflect the daily rhythm of feeding activity.

Humidification of Green Canola Seed Leads to Pigment Degradation in the Absence of Germination

Mature canola seeds (Brassica napus cv. Westar) exposed to frost during development frequently contain green pigments that discolor extracted canola oil. The green pigments must be removed from the oil by bleaching, which significantly reduces the oil yield. The quantity of pigment remaining in the oil prior to bleaching is a function of the amount of pigment and the proportion of phytylated pigments in the seeds. The objective of this study was to determine whether the quantity and chemistry of the pigments could be altered by seed humidification after harvest without leading to germination. Intact plants with seed moisture in the range of 700 to 500 g kg−1 were exposed to −15°C for 3 h. The seeds were harvested at maturity, and analysed for moisture content, pigment content, storage protein, and triacylglyceroi before and after exposure to 97% relative humidity for 10 d that increased seed moisture content to 230 g kg−1. This treatment led to a 25% reduction in total pigment content and a 35% increase in the percentage of dephytylated pigments. In vitro measurementisn dicated this was the result of chlorophyllase activity. Neither storage proteins nor triacylglycerols were mobilized during humidification. In comparison, unrestricted water imbibition led to changes associated with seed storage protein reserve mobilization within 24 h of initial imbibition. Apparently, humidification treatment has the potential to decrease canola oil pigment content without decreasing seed oil or meal quality and quantity. The recommended humidification procedure attains a seed moisture content of 200 g kg−1, which can be achieved by a 7‐d exposure to 97% RH.

A mathematical model of microalgal growth in light‐limited chemostat culture

AbstractA mathematical model for light‐limited growth of a continuous microalgal culture is proposed. Average light intensity inside the photobioreactor was calculated, taking light attenuation by algae into account. The biomass absorption coefficient was determined by means of two new parameters, the pigment‐free biomass, YB, and the total pigment absorption, Yp (absorption coefficient normalized to total pigment content). The model reproduced the steady states reached and the dynamic behaviour of the system when the dilution rate was changed.

Photo-Regulated Astaxanthin Production by Phaffia rhodozyma Mutants

Astaxanthin production by Phaffia rhodozyma mutants was photo-inducible. The intracellular astaxanthin concentration during cultivation in the dark was almost constant in the different mutants and did not reflect the concentrations reached in cells grown in the light, which differed considerably among these mutants. The final astaxanthin concentration obtained was determined by the total time of illumination, the growth phase subjected to illumination and the light intensity. Higher astaxanthin levels were obtained when cells were illuminated during the exponential growth phase. Subjecting cells to a 15 min light pulse greatly enhanced pigment production, but the stimulation was of a transient nature and a reduction in total pigment content was observed when the cultures were returned to the dark. The maximum astaxanthin production was obtained when cultures were continuously illuminated at moderate light intensities (5 to 100 µE.m-2·-1). Blue light was primarily responsible for photo-induced astaxanthin production in P. rhodozyma.

Astaxanthin production by a Phaffia rhodozyma mutant on grape juice

During fermenter cultivation of Phaffia rhodozyma on a grape juice medium, the presence of glucose initially delayed fructose utilization, although fructose was consumed before glucose depletion. Total pigment and astaxanthin production were growth associated and reached maximum values of 15.9 μg/ml and 9.8 μg/ml, respectively, after depletion of the carbon source. The total cellular pigment and astaxanthin content increased during the stationary growth phase due to a decrease in biomass, reaching final values of 2120 μg/g and 1350 μg/g, respectively, without the volumetric concentration in the culture changing. The final cell yield was 0.33 g/g sugar utilized. High sugar concentrations in shake-flasks as well as O2 limitation decreased the astaxanthin content of the cells. Addition of yeast extract to a grape juice minimal medium markedly increased the maximum specific growth rate, total pigment and astaxanthin content of the cells. An excess of ammonia decreased the intracellular astaxanthin content, which reached a maximal value in cultures with no residual glucose or ammonia.

Meat pigment determination by phase partitioning in triton x‐114 and oxidation with sodium nitrite

AbstractA method is described for determining the total pigment content of pork meat by oxidizing the pigments to metmyoglobin with sodium nitrite and using the non‐ionic detergent Triton X‐114. This detergent is used to solubilise and to increase the absorptivity of the myoglobin at the Soret band (A409). In addition, Triton X‐114 has the property of separating into two dear phases in equilibrium, one detergent‐rich and the other depleted, when the temperature is increased to 37°C. This phase separation removes all the non‐specific turbidity of the meat, which is one of the main problems encountered in determining pigment concentration and a source of inaccuracy. This method, called the Nit409/TX‐114 method, can be used in routine analysis for determing total pigment concentration in pork meat since it is accurate and rapid, and involves no toxic reagents or specialized equipment. The method can also be used to measure pigment in other meat types, even those with low pigment levels.