Determining efficient extraction procedure of phytochemicals from the fruit paste of Ziziphus abyssinica and Tamarindus indica.

Objective: To determine the most effective method of extracting metabolites from the two herbs Ziziphus abyssinica and Tamaridus. Indicus.Methodology and results: The methods used included cold and soxhlet extraction using methanol as the solvent and hot extraction using distilled water. To determine the efficiency in which compounds are extracted TLC was performed on silica gel aluminium plates using ethyl acetate: formic acid: glacial acetic acid: water (100:11:11:27). To determine the quantity of phenolic compounds in the extract, the Folin and Ciocalteau’s method (1927) was used, using Gallic acid in various concentrations. For the total quantity of flavonoid compounds, the method of Miliauskas et al. (2004) was used. To determine the Proanthocyanidin content in the extract a method previously reported by Ayoola et al, 2006 was used. To measure the antioxidant capacity of the extracts the hydrogen donating or free radical scavenging activity, was measured using the stable radical DPPH. The compounds extracted by all the methods were about seven but the difference was noted when the individual compounds were analysed. The cold extraction on the herb extract of Z. abyssinica had significantly high amount of total phenols 1.99g/100g of sample than both soxhlet and water extraction with 1.51g and 0.61g/100g of sample respectively. The results of T. indicus indicate that the extracts from the soxhlet and cold extraction methods contained a significantly low amount of all the three compounds compared to the water extractsConclusion and application of results: The method best suited for obtaining extracts from the two herbs T. indicus and Z. abyssinica is, cold method of extraction with methanol as the solvent for Z. abyssinica and hot extraction using distilled water for T. indicus. The results obtained give guidance to the fact that using both herbs would result in a better preservative than using one herb since the identified compounds would complement each other.Key words: Antimicrobial, antioxidant, phytochemicals and Radical scavenging activity

Optimal Handling and Postharvest Strategies to Reduce Losses of ‘Cuello Dama Negro’ Dark Figs (Ficus Carica L.)

The optimal postharvest handling to reduce postharvest decay and maintain quality of ‘Cuello Dama Negro’ fresh dark figs grown in Spain is been studied. Different storage temperatures (0ºC and 4ºC), relative humidity (RH, 75% to 95%) and cooling strategies (delayed and intermittent cooling) were tested. Moreover, different postharvest strategies such as 1-MCP (10 ppm), two different passive modified atmosphere packaging (Xtend® and LifePack MAP), and SO2 generating pads (UVASYS, Grapetek (Pty) Ltd.), were also tested. Storage at 0ºC, 95% RH together with MAP effectively decreased postharvest rots and therefore increased the market life of ‘Cuello Dama Negro’ fresh figs, without altering the fruit quality nor the consumer liking degree. No improvement on the shelf life of the fruit was observed with the application of 1-MCP. The use of SO2 generating pads reduced the decay but detrimentally affected fruit quality by inducing skin bleaching. Low temperature from harvest to consumption is crucial for a good maintenance of quality in fresh fig. In addition, EMAP technology is a low-cost technology able to reduce decay and maintain fruit quality of fresh figs up to 2 weeks.info:eu-repo/semantics/acceptedVersio

Evaluation of alternative preservation treatments (water heat treatment, ultrasounds, thermosonication and UV-C radiation) to improve safety and quality of whole tomato

Previously optimised postharvest treatments were compared to conventional chlorinated water treatment in terms of their effects on the overall quality of tomato (‘Zinac’) during storage at 10 °C. The treatments in question were water heat treatment (WHT = 40 °C, 30 min), ultrasounds (US = 45 kHz, 80 %, 30 min), thermosonication (TS =40 °C, 30 min, 45 kHz, 80 %) and ultraviolet irradiation (UV-C: 0.97 kJ m−2). The quality factors evaluated were colour, texture, sensorial analysis, mass loss, antioxidant capacity, total phenolic content, peroxidase and pectin methylesterase enzymatic activities, and microbial load reduction. The results demonstrate that all treatments tested preserve tomato quality to some extent during storage at 10 °C. WHT, TS and UV-C proved to be more efficient on minimising colour and texture changes with the additional advantage of microbial load reduction, leading to a shelf life extension when compared to control trials. However, at the end of storage, with exception of WHT samples, the antioxidant activity and phenolic content of treated samples was lower than for control samples. Moreover, sensorial results were well correlated with instrumental colour experimental data. This study presents alternative postharvest technologies that improve tomato (Zinac) quality during shelf life period and minimise the negative impact of conventional chlorinated water on human safety, health and environment.info:eu-repo/semantics/publishedVersio

Phytochemical studies on herbal plants commonly used for processing and preserving meat and milk

Objective: The study aims at identifying and collecting herbal plants commonly used in milk processing and preservation by the Maasai community in Kajiado district and to determine the phytochemical and mineral composition.Methodology and Results: Twenty-three herbal plants were identified; three plants were selected through community prioritization using a structured questionnaire. Analysis for phytochemical composition was done using Sofowara (1993), Trease and Evans (1989) and Harborne (1998) methods composition by AOAC method 923.03 (AOAC, 1995) and pH. Tannins, saponins, flavonoids, alkaloids, steroids, sterols, terpenoids, flavones aglycones and reducing compounds were present in all the herbal plants. The herbal plants were significantly different (P<0.05) in mineral content. The highest mineral content was calcium 90.0 mg/100 g followed by magnesium, zinc and iron.Conclusion and application of the findings: this indicates that these plants are rich in phytochemicals and minerals therefore, they can be exploited to develop nutritive food preservatives because phytochemicals have both antimicrobial and antioxidant properties. These plants can also be processed to obtain a product that will substitute the chemical preservatives in the market now that consumers are showing greater preference for products preserved with natural products.Keywords: phytochemicals, herbs, minerals, antimicrobia