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The most important genus in the Rhamnaceae family is Ber (Ziziphus mauritiana Lamk). Phytochemicals present in Ziziphus have antioxidant as well as antimicrobial properties. The present study aimed to detect various phytochemicals and evaluate the antibacterial activity in the Z. mauritiana leaf extracts. Leaves from 14 cultivars/germplasm/varieties of Z. mauritiana were used to explore the presence of various phytoconstituents such as alkaloids, flavonoids, cardiac glycosides, phenols, saponins, protein, steroids, tannins, lignins, and reducing sugar. These phytoconstituents have antioxidant, antibacterial, and hepatoprotective activities. The preliminary antimicrobial activity screening of Ziziphus leaf extract against bacterial strains-Bacillus subtilis (Gram-positive), Staphylococcus aureus (Gram-positive), Salmonella abony (Gram-negative), E. coli DH5α (Gram-negative) were performed by using well diffusion method. The results of various phytochemicals like alkaloids, phenolics, flavonoids, tannins, carbohydrates, proteins, lipids, and amino acids were reported in all selected commercial varieties/cultivars/ germplasm. On the other hand, saponins were found completely absent in methanolic solvents of all varieties/cultivars. The aqueous and methanolic solvent leaf extract were tested for antibacterial activity at different concentrations (25mg/ml, 50mg/ml, and 100mg/ml) against the bacterial strains of B. subtilis, S. aureus, S. abony, and E. coli DH5α, respectively. This study showed that the phytochemicals extracted from Z. mauritiana leaves have potential antimicrobial activities. [ABSTRACT FROM AUTHOR]

Abstract Among the hive products of stingless bees (SB), honey is distinguished because it has different physicochemical properties than the honey produced by Apis mellifera. Its taste is more acidic and less sweet, and it naturally contains a higher percentage of water. Honey is one of the most frequently adulterated products marketed. Therefore, this work aimed to verify if the qualitative tests performed for A. mellifera honey are also valid for SB honey from Tetragonisca angustula, Melipona quadrifasciata, and Tetragona elongata and if they can detect the most common adulterations. Adulterations of SB honey with corn syrup, inverted sugar, and A. mellifera honey were simulated and tested with Lugol, Fiehe, and Lund reactions. For these three analyses, sample volume reduction was also tested. The Lund test did not work well with honey samples from SB because they have a higher water content, and reliable results could not be obtained. For the other two tests, the sample volume reduction used was efficient. The Fiehe test detected adulteration with corn syrup only. The Lugol test detected corn syrup and inverted sugar adulterations in all dilutions for all three SB species. No adulteration by added water or honey from A. mellifera was detected in any test. Therefore, using the qualitative Lugol’s reaction test to evaluate SB honey quality is reasonably affordable. Since it is a rapid and inexpensive test, it allows the development of production chains for SB honey. Thus, detecting inauthentic honey can be done by combining qualitative tests as the first screening, followed by quantitative tests if necessary.

In the current study, extraction from the stem and leaf of the well‐known Indian medicinal plant Angelica archangelica (A. Angelica) with the solvents of variable polarity such as water, methanol, ethyl acetate, and chloroform is reported. The presence of different secondary metabolites like terpenoid, flavonoid, glycosides, carbohydrates, resin, steroid, proteins, and tannin are confirmed by different phytochemical qualitative test for ethyl acetate, water, chloroform, and methanol extract. The difference in the composition of all the extracts is motivated to conduct the comparison of the biological potential of all extracts in the form of DNA cleavage, DNA binding, and antioxidant activity. It is observed that the methanolic extract is most potent among all which has high concentration of terpenoids. It has shown 95% DPPH scavenging activity and 62% DNA cleavage activity. Separation of terpenoids from methanolic extracts to hexane layer is conducted which proved the same as hexane layer has shown maximum DNA binding potential. Hexane layer has shown 52% DNA binding activity. [ABSTRACT FROM AUTHOR]

Objective. The purpose of this investigation was to improve a rankit ordinal model for evaluating and validating dichotomized tests in a prospective Nordic project. Material and methods. The model is based on the assumption that the S-shaped curve of fractions of positive for increasing concentrations can be de-convoluted to a histogram and thereby used to calculate the parameters for a ln-Gaussian distribution. In a Nordic survey, four urine samples with known concentrations of hCG (human chorionic gonadotrophin) and nitrites were distributed to more than 2500 practitioners' offices. Results. The results are presented as parameters (geometric mean and CV) for the components urine-hCG and urine-nitrites, together with fractions of positive for clinical critical values (5 and 40 IU/L for hCG), for which fractions should be below 0.01 and above 0.99, respectively, and 7 µmol/L for nitrites. Furthermore, the concentration intervals of varying fractions of positive from 0.01 to 0.99 are estimated as grey zones. The parameters and grey zones for different kits are compared. No urine-hCG kit fulfilled the low clinical criterion, whereas all fulfilled the high criterion. Seven of the eight nitrites kits had fractions of positive above 0.9 for the company confirmation limit, but varying fractions for the clinically important limit of 7 µmol/L (fractions from 0.06 to 0.83). Conclusions. The present model makes it easy to estimate parameters for the kits, and also to estimate the fractions of measured positives for specified concentrations. It is thus suited for external quality assessment as well as for manufacturers' method validation. [ABSTRACT FROM AUTHOR]

The introduction of legislative microbiological criteria for foods [Official J L338 (2005) 1] has increased the exposure of enforcement and industrial laboratories to the need to test multiple food samples for organisms such as salmonellae. A consequence has been an increase in the number of organizations, both official and commercial, considering whether it is permissible to composite replicate sample units for the purposes of assessing compliance with the criteria. This note summarizes the statistical and practical aspects of compositing sample units for compliance testing. Provided that the method of choice is ‘fit for purpose’, then there is no statistical difference between testing, say, 30 × 25 g sample units or 3 × 250 g sample units. However, compositing of sample units should be done only when the method has been demonstrated unequivocally to be sufficiently sensitive to detect potentially lower numbers of target organism(s) in the quantity of composited sample under the conditions of test. Different approaches to compositing of samples are considered. [ABSTRACT FROM AUTHOR]