Principal Component Analysis Biplot Research Articles

Influence of germination on physicochemical, thermo‐pasting, and antioxidant properties of moong grain ( Vigna radiata )

Moong grains (MG) were germinated for the different time period (1, 2, 3, 4, and 5 days) and the effect of germination time on the quality of MG flour was determined. A significant (p < 0.05) increase in nutritional composition, functional properties, and antioxidant activity of MG flour was observed upon germination. In comparison to control samples, increase in protein content (27.94–35.80 g/100g), the total color difference (15.56–22.18), total phenolic content (2.31–6.84 GAE/100g), and total flavonoid content (3.82–9.35 QE/100g) occurred upon the germination. Functional properties such as WAC and OAC also increased from 1.61–3.48 g/g and 0.92–1.38 g/g, respectively, with the increase in germination time. The initial, mid, and end temperature of gelatinization decreased from 87.90 to 67.90°C, 88.00 to 98.30°C, and 88.20 to 68.70°C, respectively. Germination led to the reduction in pasting temperature and pasting viscosity of flour thereby reducing the cooking time. Principal component analysis bi-plot also demonstrated the variability in different properties of flour with respect to germination time. Practical applications Germination of food grain is a traditional practice to enhance the bioavailability of micronutrient. Germination time is an important factor affecting the physicochemical, functional, pasting, and antioxidant properties of MG. The present study will provide cumulative information for the selection of industrial and household germination process time for the desired quality end products.

Application of laser-induced breakdown spectroscopy (LIBS) coupled with PCA for rapid classification of soil samples in geothermal areas.

The Manuguru geothermal area, located in the Telangana state, is one of the least explored geothermal fields in India. In this study, characterization of the soil samples is carried out by laser-induced breakdown spectroscopy (LIBS) coupled with analytical spectral-dependent principal component analysis. A total of 20 soil samples were collected both from near the thermal discharges as well as away from the thermal manifestations. LIBS spectra were recorded for all the collected soil samples and principal component analysis (PCA) was applied to easily identify the emission lines majorly responsible for variety classification of the soil samples. In this submission, a modified PCA was developed which is based on the spectral truncation method to reduce the huge number of spectral data obtained from LIBS. The PCA bi-plot on the LIBS data reveals the presence of two different clusters. One cluster represents the soil samples collected from the close vicinity of the thermal manifestations whereas the other cluster contains the soil samples collected away from the thermal sprouts. PCA performed on the chemical dataset of the soil samples also reveals the same clustering of the soil samples. Both LIBS and chemical analysis data shows that soil samples near the thermal waters are found to be enriched in B, Sr, Cs, Rb, Fe, Co, Al, Si, Ti, Ru, Mn, Mg, Cu, and Eu concentrations compared to the soil samples located away from thermal manifestations. This study demonstrates the potential use of LIBS coupled with PCA as a tool for variety discrimination of soil samples in a geothermal area. LIBS is shown to be a viable real-time elemental characterization technology for these samples, avoiding the rigorous dissolution required by other analytical techniques.

Density, but not distribution pattern of Assiminea latericea varies on tidal flats with smooth cordgrass Spartina alterniflora invasion stage

The effect of Spartina alterniflora invasion stage on density and distribution pattern of Assiminea latericea was studied in 2014 and 2015 on the coast of the Yellow Sea, Jiangsu, China. Invasion of S. alterniflora altered the environmental properties. With the increase of invasion age, the coverage and stem density of S. alterniflora and organic matter content tended to increase, whereas chlorophyll a and salinity tended to decrease. Using principal components analysis (PCA), the habitats were separated along the gradient of the invasion stage of S. alterniflora. Coverage and stem density of S. alterniflora and salinity were the most important characters for habitat differentiation because the PCA biplot illustrated that the vectors of these environmental properties involved the smaller angles with PC 1. Based on a two-way ANOVA analysis, invasion stage of S. alterniflora and season significantly affected the density of A. latericea (p < 0.001), but their interaction was not significant (p=0. 226). The density of A. latericea varied significantly among seasons in each habitat based on a one-way ANOVA analysis, except in the bare mudflat without invasion. The highest densities occurred at the mature invasion stage in autumn, whereas the lowest densities occurred with no invasion in spring. Both Taylor’s and Iwao’s regressions indicated that A. latericea presented an aggregated distribution pattern (p < 0.001). The consistent distribution pattern indicated that it might be a biological trait of the species. Based on stepwise regression analysis, stem density of S. alterniflora and organic matter content were selected for the optimal regression model. Our results suggest that S. alterniflora invasion altered the environment of the coast and variation in A. latericea density was a response of the species to the environmental change caused by S. alterniflora invasion. Food resources, temperature, biological traits, and predation risk should be comprehensively considered.

Quality profile determination of palm olein: potential markers for the detection of recycled cooking oils

ABSTRACT In this study, the safety and quality of commercial cooking oils were evaluated. The emphasis of this evaluation was on the presence of oxidation and polymerization products in fresh oils, although the analyses were often conducted on used frying fats and oils. This was because polymerized triacylglycerols (PTGs) and monomeric oxidized triacylglycerols (oxTAGs) have been proposed as potential indicators of the adulteration of palm olein. The oil quality was evaluated based on PTG content, the presence of epoxy, keto, and hydroxy acids, fatty acid composition, and smoke point. Principal component analysis (PCA) was conducted to identify the relationships among the analytical parameters. The total polar compound content of all fresh oil samples was within the safety limit for human consumption (< 25% polar compounds). TAG oligomers or epoxy, keto, or hydroxy acids were not detected in any of the fresh oil samples. Most of the packet oils had lower smoke point (< 200 °C) and linoleic acid content than the bottled oils. The pure palm olein samples were found to be better in terms of overall oil quality, as indicated by the PCA biplots of all analytical parameters. Abbreviations: ANOVA: analysis of variance; BPO: blended palm olein; DAG: diacylglycerol; FAME: fatty acid methyl ester; FFA: free fatty acid; HPLC: high-performance liquid chromatography; HPSEC: high-performance size exclusion chromatography; PC: principal component; PO: packet pure palm olein; PPO: pure palm olein; PCA: principal component analysis; SPE: solid-phase extraction; TAG: triacylglycerol; TPC: total polar compound

ATR-FTIR FOR DISCRIMINATION OF ESPRESSO AND AMERICANO COFFEE PODS

Roasted and ground coffee for encapsulation in single-serve capsules compatible with keurig® and coffee powder obtained from Nespresso® commercial capsules were analyzed for pH value, titratable acidity, moisture content, water activity and color (lightness); a data matrix that contains the physicochemical properties and the absorbance measurements using a baseline of 1600 to 1800 cm–1 by FTIR-ATR technique, was evaluated through the combined methods of principal component analysis (PCA) and cluster analysis in order to discriminate between the types of capsules. In the PCA biplot two distinct groups can be identified and in the cluster analysis two groups are that correspond to the two types of capsules. The results showed that FTIR-ATR based methods seem to be a promising alternative for the discrimination of coffee samples for the pods industry or for the type of consumption.

Geo-statistical and multivariate analyses of potentially toxic elements' distribution in the soil of Hainan Island (China): A comparison between the topsoil and subsoil at a regional scale

Geo-statistical and multivariate analyses are effective methods to determine the source and influence factors of potentially toxic elements (PTEs) in the soil. Hainan Island, belonging to tropical marine monsoon climate, is a typically individual island with slight industrial activities. In order to study the impact factors on PTEs distribution in the soil at a regional scale, such as impact of lithology, pedogenesis and anthropogenic activities, Hainan Island is an optimal place. For comparison, the topsoil and the corresponding subsoil were sampled and eight PTEs were analyzed respectively. The concentrations of PTEs were counted, such as minimum, maximum, median and mean values. Based on it, the background values and concentration enrichment factors of PTEs were also calculated or illustrated. Exception to Cd and Hg, the concentration of other PTEs in the topsoil were lower than those in the subsoil for all lithological areas since the strong leaching under special climate. By using geo-statistical and multivariate analyses, such as Pearson correlation analysis, principal component analysis, variography and robust biplot analyses, the dominant impact factors are determined for PTEs both in the topsoil and subsoil. Thus, the spatial distribution of PTEs is well explained at a regional scale. Generally, PTEs in the soil represent the components of soil parent materials associated with lithological rocks. Nevertheless, Co, Cr, Cu and Sc elements were dominantly inherited from soil parent materials while Cd, Hg and Pb were greatly superposed by exogenous inputs. On the other hand, elements of As and Zn might be greatly influenced by pedogenesis and weathering process. So, geo-statistical and multivariate analyses are effective methods to discuss the sources or impact factors for PTEs in the soil, and also the comparison between the topsoil and the subsoil provides an opportunity to illuminate the main impact factors on PTEs at a regional scale, including parent materials, weathering process and anthropogenic inputs.

Factors controlling the petroleum generation characteristics of Palaeogene source rocks in the Austrian Molasse Basin as revealed by principal component analysis biplots

Abstract After Rock-Eval & TOC screening and heterogeneity evaluation on 91 Palaeogene source rock samples from a well drilled in the Austrian Molasse Basin, ten shale samples were selected for detailed investigations by means of pyrolysis-gas chromatography, bulk kinetics and biomarker identification and quantification. Afterwards, 2-D biplots based on principal component analysis were applied to unravel the palaeo-environmental control on the development of petroleum source rocks. All samples are immature source rocks with good petroleum generation potentials. The redox environment during deposition was generally reducing, and palaeosalinity is suggested to be the main factor causing the differences in organic carbon contents among the samples. The hydrogen index values, the gas generation preferences and the aromaticity of the products are controlled by both depositional environment and precursors, and the product of a salinity indicator (MTTC) and the oleanane index is introduced as predictive proxy to evaluate these features. The maturity indicator (Tmax) is revealed as dominated by the stability of the kerogen structure which is controlled by the proportion of organic sulphur compounds in the kerogen. The global Eocene-Oligocene climate change from a greenhouse to an icehouse world is suggested to play an important role in changing the palaeoenvironment and further in influencing the development of petroleum source rocks by triggering upwelling, increasing the palaeo-sea water salinity and decreasing the deposition of carbonate-minerals. The chemometric method suggested here acts as a powerful tool in identifying the controlling factors for the petroleum generation potential among many variables, and can be applied more widely in petroleum geology when multi-parameters are involved to get quick and meaningful correlations.

Interrelation between thermal behaviour and pasting properties of malted rice using multivariate analysis

The interrelation between thermal behaviour and pasting properties in malted rice, affected by time/temperature of germination, was established using multivariate analysis. Two paddy cultivars, low (RLA) and normal amylose (RNA) were germinated at 30 and 35 °C for120 h. Thermal behaviour from DSC plots (onset, peak and conclusion temperatures) of rice increased with germination time; RNA showed a higher decrease in pasting properties compared to RLA. A biphasic pasting curve for malted RLA indicated amylose-lipid complex formation during heating. This complex resulted in increasing trends of all DSC parameters. The principal component analysis biplots of RLA at both temperatures showed that the position of amylose was loaded away from the vicinity of pasting and thermal properties; in RNA, amylose content was in the neighbourhood of these properties. Inter-relationship between the pasting and thermal behaviour of malted rice existed; the information might help for developing malted rice-based weaning and functional foods.

Multivariate analysis to evaluate indium behavior at the copper phthalocyanine thin film

In this paper, we demonstrate the application of multivariate chemometric analysis to enhance information available from photoelectron spectra for the metal-organic interface: indium on copper phthalocyanine (CuPc). The previous studies conducted by Aristov et al. [Phys. Rev. B 72, 165318 (2005)] and Ivanco et al. [Phys. Rev. B 81, 115325 (2010)] reported inconsistent and contradictory findings about the chemical reaction between In and CuPc at the initial stages of interface formation. The study of changes in ultraviolet photoelectron spectra (UPS) by principal component analysis (PCA) provides evidence for the coexistence of two types of indium phases, “reactive” and “non-reactive,” whose behavior is of importance for devices based on multilayer metal-organic semiconductors. The key information about the metal-organic chemical reaction has been gained from a PCA biplot. This characteristic graph simplifies interpretation of the UPS spectra and enables to estimate the number of pronounced peaks, their energetic positions, and the strength of correlation between them. To detect one of the indium phases, not clearly observed in the experimental spectra, we propose a new concept based on PCA methodology for an enhancement of the UPS spectra resolution. Moreover, we confirm a co-existence of different indium phases by the multivariate curve resolution alternating least square (MCR) analysis on the experimental data. We have found satisfactory agreement between the identified model and experimental data.

Multivariate Analysis of Rotifers Community from Safari Zoo Lake Lahore, Pakistan

Rotifers are zooplanktons that react more sharply to the environmental changes.&#x0D; Objective:To better understand the community composition of rotifers in Safari Zoo Lake, Lahore, PakistanMethods:We collected 16 water samples on monthly basis, dividing lake into four major sites: northern,southern, eastern, and western sites. Each of these was further subdivided into four locations, for a totalof 16 sampling sites. A total 23 rotifer species were recorded from the lake with Brachionus calyciorushaving maximum abundance. A species abundance curve was plotted between months and number ofspecies of rotifers indicating their lowest and highest abundance through the study period.Results:A Cluster Analysis yielded three main groups of closely related species including species likeBrachionus quadridentatus, Synchaeta stylata and Brachionus calyciorus etc. We used a PrincipalComponent Analysis (I and II) to study variation in the rotifer community on a seasonal basis and amongsampling sites. A biplot of Principal Component Analysis (PCA I) reected the relationship of rotifers withthe months. Some of the species showed a positive positive relationship, while others showed negativeone. PCA II was plotted between months and physico-chemical parameters showing their negative andpositive relations.Conclusion:We conclude that a lesser replacement of fresh water, increased density of waterfowl, reptilia andsolid waste left over during boating has resulted in eutrophication of lake leading to overall low diversity ofrotifers observed.

Effect of compositional data in the multivariate analysis of sterol concentrations in river sediments

In this paper, multivariate analysis of sterol concentrations detected in river sediment samples was performed. In order to remove co-dependence of values, concentrations of sterols were transformed using centered log-ratio (CLR) transformation. The main objective of the work was to point out the damaging effects of working in the wrong geometry on the principal component analysis (PCA) assessment of sterol pollution. In order to determine if the dimension lost have effect on the principal component analysis of sterols in sediments, we have performed the PCA using raw and log-ratio transformed sterol data. Additionally, two rounded zero replacement approaches, i.e. a simple-substitution method (DL/2, 0.55DL and DL/√2) and multiplicative replacement strategy (0.65 DL), were compared in order to determine if the replacement values have an effect on PCA results and conclusions. Relevant differences were noted by comparing the results of the principal component analysis obtained with raw data and log-ratio transformed sterol data. Only the PC loadings obtained from the CLR PCA allowed the clear distinction between human-sourced pollution and biogenic sources of sterols, whereas in the case of PCA with raw data loadings were all grouped almost in a single quadrant. For the small proportion of rounded zeros (not more than 10%), two different replacement approaches did not have any effect on transformed PCA output. The results presented in this work have shown that the effect of “closure” in the sterol data can be easily observed from the PCA biplot, and that it obstructs the evaluation of human contribution to pollution of river sediments. Therefore, prior to the PCA, sterol concentrations must be CLR transformed in order to perform a reliable assessment of the sewage contamination.

Simultaneous quantification of Precocene I and Precocene II through high-performance thin layer chromatography validated method in Ageratum conyzoides L. germplasms from western himalayas

Background: Ageratum conyzoides L. is a traditionally used herb for various ethnoveterinary purposes. There are no earlier reports on simultaneous high-performance thin layer chromatography (HPTLC) quantification of bioactive markers. Objective: To develop a sensitive, robust, and replicable HPTLC method for simultaneous estimation of precocene I (PI) and precocene II (PII) in A. conyzoides L. collected from the Western Himalaya region of India, with an aim to understand the level of chemotypic differences arising in the intraspecific population of this ethnobotanically important plant. Materials and Methods: A sensitive HPTLC method was developed to resolve PI and PII using toluene: ethyl acetate (9.8:0.2 v/v) as mobile phase. The method was validated for selectivity, specificity, linearity, and precision as per International Conference on Harmonization guidelines. Results: Good linearity was achieved over a five-point concentration range with a correlation coefficient of 0.986 and 0.988 for PI and PII, respectively. The PI content varies in the range of 0.0016% (NAC-77) to 0.0834% (NAC-82), whereas PII was reported to be present in the range of 0.016% (NAC-85) to 0.143% (NAC-91) on a dry weight basis. A principal component analysis biplot of samples based on the content of PI and PII identified four elite chemotypes, namely, NAC-81, NAC-82, NAC-85, and NAC-91. Conclusion: The study identifies superior germplasms for commercial prospection and develops a validated method that can be used for the quality control of herbal drug/formulation using A. conyzoides as an ingredient. Abbreviations used: HPTLC: High performance thin layer chromatography, PI: Precocene I, PII: Precocene II, ICH: International conference on harmonization, SD: Standard deviation, RSD: Relative standard deviation

Effect of ingredients on the quality characteristics of gluten free snacks.

Grain-based fabricated snacks from non-wheat grains (amaranth, finger millet, sorghum and black gram) were used to prepare puffed snacks employing the method of hot air toasting. The functional characteristics and sensory attributes of the snack were determined by varying the moisture content and time of toasting. The quality attributes of the snacks like the instrumental color parameters, peak force and puff thickness of the snack correlated well with the sensory attributes (appearance/color, texture and overall acceptability). A snack made from amaranth showed a bright reddish brown colour at a moisture content of 20-40%; the product had a good puffing and high overall acceptability. The moisture content of all the snacks was around 3% and had a fat content of 1-2%; protein and dietary fiber contents were in the ranges of 22-23 and 10-11%, respectively. The principal component analysis (PCA) accounted for a total of 89.6% variation. The PCA biplot showed that sensory appearance, sensory texture and sensory overall acceptability were closely related to the puff thickness. The microstructure of the snack indicated the presence of air cells to offer a porous structure. On toasting, the flakes increased their thickness creating a porous microstructure such that the toasted snacks were crispy having a brittle texture. Popped sorghum and gelatinized starch added doughs exhibited good puffing when toasted at 20-30% moisture content while popped amaranth samples required higher moisture content (30-40%). The grain based gluten-free snacks with improved sensory and nutritional characteristics can be prepared by using different ingredients.

Variation in the performance of contrasting maturity class of cowpea cultivars (&lt;i&gt;Vigna unguiculata&lt;/i&gt; L. Walp) in the derived Savanna

Three field trials (2009, 2010 and 2011) were established at the Teaching and Research Farm of the Federal University of Agriculture, Abeokuta (7°38′N, 3°88′E; 450 m asl). The trials aimed to evaluate the performance of cowpea cultivars of contrasting maturity class in the derived savanna. Four short and seven medium duration (local check inclusive) cowpea cultivars were sown in a randomised complete block design, replicated three times. Across the years cowpea cv. IT98K-573-2-1 (short duration) had the significantly (p &lt; 0.05) highest seed yield (2486 kg ha-1), an observation that could be attributed to its pod yield (3651 kg ha-1), stand count (73.1) and earliness (49.22 days). Cowpea cv. IFE-98-12 (medium duration) produced significantly low pod weight (1826 kg ha-1), with the least shelling weight (613 kg ha-1) and stand count (44.87) across the years. Three clusters of cowpea cultivars were identified in Principal Component Analysis biplot. They were identified based on their superior performance on seed yield, duration of development and dry fodder weight for short duration, medium duration and local check, respectively. It is concluded that these attributes could form the basis of their use and crop improvement programme in the derived savanna.Keywords: Earliness, medium duration, shelling weight, short duration

Regional, seasonal, cultivar and crop-year effects on sugarcane responses to residue mulching

Inconsistent agronomic responses of sugarcane (Saccharum spp.) to residue mulching are due to complex interactions between soil, climatic, management and genetic factors. Information on mulch responses of diverse cultivars in contrasting environments, over multiple ratoon crops, in different cropping seasons (winter vs summer) are limited. This study aimed to quantify mulch responses in three diverse environments typical of the South African sugarcane industry and to identify factors causing such responses. Three separate factorial experiments (eight cultivars, burnt or mulched at harvest) were established in the rainfed, irrigated and temperate regions of the industry, harvested over multiple ratoon crops (up to six), with summer and winter crop starts. Mulching was significantly beneficial to cane yields in the rainfed trial (up to 20t/ha improvement in a single crop), marginally beneficial in the irrigated trial, and unfavourable in the cooler temperate trial. The effects of cultivar and season (winter vs summer crop start) were negligible in comparison to regional and crop-year effects. Cultivar sensitivities to mulching were only evident in the temperate trial. A principal components analysis (PCA) biplot separated crops according to their responses to mulching and identified climatic factors responsible for differential responses. Water availability (as represented by a crop model derived drought index) was a primary driver of positive yield responses in the rainfed trial and the differential ratoon responses observed in the irrigated trial. Mulch responses in the irrigated trial were rainfall dependent, ranging from 0 to 20% improvements in water limiting years, to negative responses when water was not limiting. Low temperatures created by the residue layer was identified as a cause of negative yield responses observed in the temperate trial, mainly through delayed canopy development effects. Multivariate methods such as PCA are recommended to identify climatic, soil, genetic and management causes of differential mulch responses in sugarcane, either through analysis of multi-environment experiments or through meta-analysis of available literature.

Immunogenicity characterization of hexaploid and tetraploid wheat varieties related to celiac disease and wheat allergy

ABSTRACTWheat is one of the major cereals consumed throughout the world; there has been a radical increase in the population suffering from many wheat-related disorders. The present study was conducted to screen low immunogenic hexaploid and tetraploid wheat varieties. A total of 34 different wheat varieties were tested for its total protein content, gliadin content and immunoreactivity with immunoglobulins of celiac (IgA) and wheat allergy patients (IgE). The wheat varieties HD-2851 and NIAW-917 (hexaploid) and NIDW-295, UAS-428, PDW-291, MPO-1215 and DDK-1025 (tetraploid) were found to be less immunoreactive varieties for both celiac and wheat allergy patients. The immunoblot assays for IgE reactivity have revealed that gliadin subunits present in all varieties are found to be allergic proteins. The principal component analysis biplot showed that tetraploid wheat varieties are less immunoreactive than hexaploids. The low immunogenic wheat varieties are suitable for plant breeding and preparation of low gluten or hypo-immunogenic products.

Frying of rice flour dough strands containing gum Arabic: texture, sensory attributes and microstructure of products.

The effects of rice flour (50-56%, w/w) and gum Arabic (0-5%, w/w) on the physical, sensory and structural features of the fried dough strands were investigated. Up to 25.8% reduction in oil was possible by the incorporation of gum Arabic. The wide variations in failure force (13.8-25.3N) and failure strain (11.0-28.6%) indicated the formation of snacks varying in texture from a soft-to-bite brittle product to a hard-to-eat less brittle sample. The snacks possessed a porous microstructure with air cells, pores and vacuoles; the cell walls were more than 100μm in thickness. The textural parameters like failure force, failure energy and failure stress behaved in a similar manner in the principal component analysis biplot. High moisture content in the dough decreased the sensory acceptance of the fried snacks. The high desirability index of 0.9 could be achieved with a high level of rice flour (56%, w/w) while gum Arabic content was between 3.50 and 3.75% (w/w).

Selected physicochemical properties of starches isolated from ten cassava varieties reveal novel industrial uses

Although cassava is of great importance as a starch source for industrial purposes or food consumption, the evaluation of different varieties is an under‐investigated topic. Thus, in order to contribute to the identification of cassava starches more suitable for use and application in the food industry, this study aimed to analyze and compare the physicochemical properties of starches from ten different cassava varieties of household consumption, industrial use, and mixed use. In order to accomplish this goal, analyses were performed into the thermal and pasting properties, granule size, and amylopectin branch‐chain‐length distribution and amylose and phosphorus contents, as well as scanning electron microscopy (SEM) images of the starches. In addition, a principal component analysis (PCA) biplot was generated, as one of the most useful methods to analyze multidimensional datasets with quantitative variables. Significant differences in phosphorus and amylose contents, branch‐chain‐length distribution of amylopectin, starch granule diameter, gelatinization and retrogradation temperatures, and pasting properties were obtained. Therefore, this study adds to the literature regarding the physicochemical properties of starches of these cassava varieties, contributing to improving their uses in the food industry by novel applications these starches, and adding and corroborating uses of some varieties studied.

Occurrence and Distribution of Arsenic, Antimony and Selenium in Shallow Groundwater Systems of Ibadan Metropolis, Southwestern Nigerian.

Background.Arsenic, antimony and selenium contamination of groundwater is of great concern due to the potential detrimental effects to human health.Objectives.This study investigates the occurrence and distribution of arsenic, antimony and selenium in the shallow groundwater system of Ibadan metropolis, southwestern Nigeria.Methods.A total of 210 groundwater samples were collected from 35 shallow wells (3.15–7.86 m) within the residential, commercial, industrial and agricultural areas of the metropolis during the dry and wet seasons. The average daily dose intake (ADD), hazard quotient (HQ) and hazard index (HI) of arsenic, antimony and selenium exposure in groundwater were calculated from these four studied areas for children and adults.Results.Average concentrations of arsenic, antimony and selenium in groundwater ranged between 2.17±3.49 to 33.8±37.2 μg/L, 13.5±15.0 to 33.2±36.8 μg/L and 7.33±6.22 to 46.3±22.4 μg/L, respectively. A corresponding analysis relay plot showed the order of occurrence of these trace metals in groundwater to be antimony>selenium>arsenic. The principal component analysis biplot showed that arsenic, antimony and selenium were fairly distributed in all of the study areas, suggesting the influence of geogenic factors. A total of 74.3% of sampling locations had antimony levels slightly above the World Health Organization (WHO) safe limit of 20 μg/L. Statistical t testing (0.05 confidence limit) showed a significant difference in seasonal levels of groundwater antimony concentration, with the dry season recording significantly higher levels with 100% of samples exceeding WHO safe limits. The chemical of highest potential human health concern is antimony, with a non-carcinogenic HQ risk factor >2 for both age groups. The overall non-carcinogenic HI was highest in the commercial area, 4.1989 for adults and 5.2487 for children.Conclusions.Antimony in groundwater within the Ibadan metropolis raises health concerns and a concerted effort is needed to identify its sources to avoid the risk of antimony toxicity.

Development of class model based on blood biochemical parameters as a diagnostic tool of PSE meat

A fast, sensitive and effective method based on the blood biochemical parameters for the detection of PSE meat was developed in this study. A total of 200 pigs were slaughtered in the same slaughterhouse. Meat quality was evaluated by measuring pH, electrical conductivity and color at 45min, 2h and 24h after slaughtering in M. longissimus thoracis et lumborum (LD). Blood biochemical parameters were determined in blood samples collected during carcass bleeding. Principal component analysis (PCA) biplot showed that high levels of exsanguination Creatine Kinase, Lactate Dehydrogenase, Aspertate aminotransferase, blood glucose and lactate were associated with the PSE meat, and the five biochemical parameters were found to be good indicators of PSE meat Discriminant function analysis (DFA) was able to clearly identify PSE meat using the five biochemical parameters as input data, and the class model is an effective diagnostic tool in pigs which can be used to detect the PSE meat and reduce economic loss for the company.