Persistence and diffusion behaviour of chlorpyrifos in five different species of vegetables: A comparative analysis.

Understanding of pesticide persistence and diffusion on the fresh vegetables are extremely important in food safety and decontamination process. In this study, we examine the persistence and diffusion behaviour of chlorpyrifos pesticide in five different species of vegetables. The chlorpyrifos pesticide was spiked on the vegetable surfaces and the extracted samples from peel and tissues were subjected to Gas Chromatography equipped with a Flame Photometric Detector (GC-FPD). Further, the chlorpyrifos diffusion behaviour was compared with the osmotic potential, shear strength, cuticular chemical profile and microstructure of peel surface of vegetables. The persistence analysis results revealed that chlorpyrifos level was decreased in peel surface and diffusion rate was increased in inner tissue with respect to durations. Within 72 h exposure, chlorpyrifos reached 0.7 cm depth into the inner tissue of vegetables. Significant level of chlorpyrifos diffusion with P ≤ 0.05 was observed in beetroot (2.47%), khon khol (1.46%) and brinjal (0.92%) compared to cucumber and potato. Remarkably, there was no direct linkage between the chlorpyrifos diffusion rate, osmotic potential and toughness of vegetables. In addition, the Gas Chromatography Mass Spectroscopy (GC-MS) and Scanning Electron Microscopy (SEM) analyses revealed that epicuticular surface microstructure and chemical profiles were not correlated with the chlorpyrifos diffusion in all the tested vegetables. The study results concludes that chlorpyrifos diffusion is vegetable species specific and it is highly variable between the species.

Effect of edible coating on the aromatic attributes of roasted coffee beans.

Coffee is known throughout the world for its distinct aroma and flavour which results from a number of volatile compounds present in it. It is very difficult to arrest the aromatic compounds once the roasting process is complete and it becomes even more challenging to store the beans for a longer time with the retained volatiles as these compounds are easily lost during industrialized processing such as the grinding of roasted coffee beans and storage of ground coffee. Thus, an attempt was made to minimise the loss of volatile from roasted coffee beans by coating with Carboxymethyl cellulose (CMC), Hydroxypropylmethyl cellulose (HPMC) and Whey protein concentrate. Coffee volatiles were analysed by Gas chromatography and 14 major compounds were identified and compared in this study. Results showed an increase in the relative area of major volatile compounds in coated roasted coffee beans when compared with unroasted coffee beans for consecutive two months. Moreover, effect of coating on textural properties and non-volatiles were also analysed. The results have indicated that edible coatings preserve the sensory properties of roasted coffee beans for a longer shelf life and cellulose derivatives, as an edible coating, exhibited the best protecting effect on roasted coffee beans.

Roasting green coffee beans using spouted bed roaster: changes in physical characteristics.

Pea-berry grade of green coffee (Coffea arabica) beans were roasted in a laboratory model spouted bed roaster at different temperatures (150-250°C) and times (30-300 s). The roasted samples were analysed for instrumental colour (hue, chroma and brightness) and texture. Brightness of the roasted samples varied between 5.2 and 20.4%, and time of roasting markedly decreased the brightness values. The chroma showed a curvilinear decrease with both time and temperature of roasting; the lowest values were with highest roasting times and temperatures. The hue or dominant wavelength increased from 576 to 603 nm due to roasting. The maximum force offered by the roasted beans decreased with temperature and/or time of roasting. An appropriate condition for spouted bed roasting of green coffee beans was obtained considering colour of samples and desirable low failure/fracture force.

A comprehensive review on utilization of wastewater from coffee processing.

The coffee processing industry is one of the major agro-based industries contributing significantly in international and national growth. Coffee fruits are processed by two methods, wet and dry process. In wet processing, coffee fruits generate enormous quantities of high strength wastewater requiring systematic treatment prior to disposal. Different method approach is used to treat the wastewater. Many researchers have attempted to assess the efficiency of batch aeration as posttreatment of coffee processing wastewater from an upflow anaerobic hybrid reactor (UAHR)-continuous and intermittent aeration system. However, wet coffee processing requires a high degree of processing know-how and produces large amounts of effluents which have the potential to damage the environment. Characteristics of wastewater from coffee processing has a biological oxygen demand (BOD) of up to 20,000 mg/l and a chemical oxygen demand (COD) of up to 50,000 mg/l as well as the acidity of pH below 4. In this review paper, various methods are discussed to treat coffee processing wastewaters; the constitution of wastewater is presented and the technical solutions for wastewater treatment are discussed.