The value of a scientific analysis and the significance of the results are influenced by the degree to which the sample analyzed reflects the composition of the material or population under study. An appropriate methodology will result in representative sampling. Formulae for representative sampling protocols were evaluated, and an optimal formula to be used in a sampling plan for “street” drug exhibits with a large number of units was selected. The selected formula was applied to choose a number of sample units for routine chemical analysis of controlled substances, with the analytical result considered to be representative of the entire lot of powdered drug units in the exhibit. The results obtained during the research demonstrate that adoption of the formula n = 20 + 10%(N − 20) [where n = sample size, N = total population (N ⩾ 20)] can be used for selection of an appropriate representative sample from powdered street-drug exhibits. This sampling procedure results in forensic analyses of controlled substances which are supportable to a reasonable scientific certainty, and which are obtained in an efficient manner.

Ackee (Blighia sapida K. D. Koenig) is an exotic fruit widely consumed in the Caribbean countries. While there is extensive research on the presence of hypoglycin A, other bioactive compounds have not been studied. We identified and quantified the changes in bioactive molecules (total phenol, ascorbic acid, hypoglycin A, squalene, D: A-Friedooleanan-7-ol, (7.alpha.), and oleic acid), antioxidant potential, and volatile compounds during two stages of ripe. A clear reduction in hypoglycin A, ascorbic acid, and total polyphenols during the maturation process were observed. On the contrary, oleic acid, squalene, and D: A-Friedooleanan-7-ol, (7.alpha.) contents increased about 12, 12, and 13 times, respectively with advancing maturity. These bioactive molecules were positively correlated with radical scavenging (DDPH and ABTS). Solid phase microextraction (SPME) and gas chromatography coupled mass spectrometry (GC/MS) analysis revealed more than 50 compounds with 3-penten-2-one and hexanal as the major compounds in the fully ripe stage. The results suggested that ripe ackee arilli could serve as an appreciable source of natural bioactive micro-constituents.

ResumenSe determinó la cinética de pérdida de agua en chips de arveja (Pisum sativum L.) de la variedad Obonuco Andina en diferentes condiciones de fritura a presión atmosférica y de vacío. Se consideraron tres presiones (78, 43 y 9 kPa) asociadas a tres temperaturas (140, 160 y 180 °C), y se utilizó una relación semilla/aceite 1:8 (p/v), tomando mediciones entre 0 y 240 segundos. El efecto de la presión y la temperatura fue evaluado mediante el coeficiente de difusión (Deff) y la energía de activación (Ea), mientras que las cinéticas de pérdida de agua fueron estudiadas con tres modelos (Newton, HendersonPabis y Page). Se determinó dependencia de la difusividad con la temperatura y la presión. La ecuación de Arrhenius dio valores de la energía de activación Ea de 18.67, 13.82 y 13.75 kJ/mol, para 78, 43 y 9 kPa respectivamente. Los modelos expuestos describen adecuadamente la cinética de pérdida de agua.Palabras clave: pérdida de agua; difusividad; energía de activación; constante cinética; Pisum sativum L. Kinetics of Water Loss in Chips of Peas (Pisum Sativum L.) by Conventional and Vacuum Frying Conditions AbstractThe kinetics of water loss from chips peas (Pisum sativum L.) of Andina Obonuco variety in different frying conditions at atmospheric pressure and vacuum was determined. Three pressures were considered (78, 43 and 9 kPa) associated at three temperatures (140, 160 and 180 °C), and a seed/oil ratio 1: 8 (w/v) was used taking measurements between 0 and 240 seconds. The effects of pressure and temperature were evaluated by the diffusion coefficient (Deff) and the activation energy (Ea), while the kinetics of water loss was studied with three models (Newton, Henderson-Pabis and Page). The dependence of diffusivity on temperature and pressure was determined. The Arrhenius equation gave values for the activation energy Ea of 18.67, 13.82 and 13.75 kJ/mol at 78, 43 and 9 kPa respectively. The models analyzed in this work adequately describe the kinetics of water loss.