Nawaf Abu-Khalaf

Detecting plant diseases using visible/near infrared spectroscopy

Introduction P alestine Technical University– Kadoorie (PTUK) is one of 13 higher educational institutes in Palestine. PTUK is the first and only technical and governmental university in the West Bank. It is located on the western side of the city of Tulkarm and serves the Palestinian community in the Palestinian governorates. PTUK was established in 1930 as an agricultural school (Figure 1) and was then developed to provide Diploma programmes in various disciplines. The university went through different phases of development until it was accredited as a university on August 2007 to provide technical programmes at various levels including Diploma and Bachelor degrees in different areas in engineering and applied technology. Currently there are about 5000 students enrolled in PTUK. PTUK is particularly interested in teaching and delivering knowledge of applied science in the fields of agricultural and evnironmental sciences. On the basis of its three units (biotechnology, water and environment, and agriculture), PTUK established the Technical and Applied Research Center (TARC) in 2009. Several research projects are being conducted at TARC including phytopathology, soil, air and water pollution as well as sensor technology for non-destructive quality assesment of agricultural commodities. PTUK is very interested in the olive sector in Palestine, since olive trees cover approximately 45% of Palestinian agricultural lands. The tree is very important in the economic and social lives of the population, as it accounts for one of their main sources of income; in a good year, it can contribute about 13% of the annual agricultural production. The olive (Olea europaea L.) is one of the oldest agricultural trees and is cultivated over large areas in Palestine, with more than 10 million olive trees (about 67.3% of all horticultural trees) being grown. Olive production contributes about 12–13% of national income. The olive tree is affected by many pests and diseases. Olive leaf spot (OLS) is a foliar disease which is widespread in all olive growing regions of the world and has been reported in Mediterranean areas (Figure 2). As a result of infection, yield losses occur and these can amount to up to 20% of total production. Olive leaf spot is chemicallycontrolled by application of copper (Cu) fungicides directly after harvest but chemical treatment rarely appears to be effective. Moreover, using chemical fungicides leads to the appearance of pathogen races which are resistant to Cu as well as more general imbalance of the plant metabolism following Cu accumulation in the soil. In Palestine, the disease is common throughout many areas of the southern and northern parts of the country. The Palestinian Ministry of Agriculture, NGOs and several private institutions work with the olive sector to provide guidance and information about improving olive crop production and protection. Visible/near infrared (vis/NIR) spectroscopy is a mature sensor technology that has been successfully applied to the noninvasive analysis and detection of many parameters (for example, quality, stress and presence of disease) of a wide range of agricultural commodities. Due to its success, vis/NIR spectroscopy was used in this feasibility study to detect the severity of OLS disease in olive trees.

The Taste of Commercially Available Clarithromycin Oral Pharmaceutical Suspensions in the Palestinian Market: Electronic Tongue and In Vivo Evaluation

Background: The taste of oral liquid dosage forms is a crucial factor that impacts paediatric patient compliance. The electronic tongue (ET) is an emerging tool that could be useful in taste assessment in order to minimize the involvement of humans in such evaluations. Purpose: The aim of this study is to evaluate the taste of commercially available clarithromycin (CM) oral pharmaceutical suspensions in the Palestinian market. Method: Commercially available CM suspensions (the brand Klacid® and two generic K1 and K2) were assayed using the high performance liquid chromatography (HPLC) method. Then, the taste of these products was assessed using alpha-astree ET. In addition, an in vivo taste assessment was conducted on paediatric patients by a hedonic panel test. Moreover, volunteering community pharmacists were asked to rank the taste of these three products according to their experience from the best to the worst. Results: All suspension products had a CM concentration not less than 98% of the label amount. The ET results coupled with the principal component analysis (PCA) showed a very clear discrimination of the samples with different distances between groups (p-values < 0.001). Suspensions were in the following order in terms of taste: Klacid® > K1 > K2. Moreover, The pattern discrimination index between (K1 and Klacid®), (K1 and K2) and (Klacid® and K2) were 8.81%, 65.75%, and 71.94%, respectively which suggests that K1 and Klacid® are the most similar preparations in terms of taste. Interestingly, these results were in excellent agreement with the pharmacist ranking and patient acceptance test. Conclusions: The evaluated preparations showed significantly different taste within the order of Klacid® > K1 > K2, as suggested by both the ET and in vivo results. Moreover, our results confirm the capability of alpha-astree ET in the taste assessment of oral suspensions and in predicting volunteer responses, which highlights its beneficial use as an in vitro taste assessment tool and as an alternative to human-based taste evaluations.

Sensing Taste Attributes of Plums Using Near Infrared (NIR) Reflectance Spectroscopy

In recent years, research has been focused on the development of nondestructive techniques for measuring quality parameters of different agricultural commodities. The aim is development of techniques which include fast execution, can easily be used in process control and grading system and requires limited sample pre-processing (Lammertyn et al., 2000). NIR spectroscopy is one of these non-destructive techniques. NIR methods have already been used to detect bruised on apples (Upchurch et al., 1994) and to study dry matter content in onions (Birth et al, 1985) and potatoes (Dull et al, 1989). Kawano et al. (1992) used an optical fibre with interactance mode to study the sugar content in peaches. Slaughter (1995) managed to measure non-destructively the internal quality of peaches and nectarines as characterised by their soluble solid content (SSC), sorbitol and chlorophyll contents using visible and NIR spectroscopy. Bellon et al. (1993) used the wavelength region between 800–1050 nm and developed a NIR instrument coupled with optical fibres to detect sugar at the speed of three apples per second with a standard error of prediction of 2.4 g/1 of glucose. A relationship between NIR spectra and apple fruit quality parameters such as pH, acidity, sugar content and texture parameters was established by Lammertyn et al. (1998) and Moons et al. (2000).