Browsing by Author "Kazosi, Marynurce"

Now showing 1 - 3 of 3

Development of dried African nightshade products for post-harvest loss reduction and shelf-life extension in Tanzania
(NM-AIST, 2023-07) Kazosi, Marynurce
African nightshade (ANS) is a luminary food plant, considered a cheap and potential dietary source for micronutrients and bioactive compounds. Lack of value addition on ANS, results to high availability of ANS during peak season and shortage in off-season was the great demand for developing dried products. This study evaluated the effects of drying techniques on nutritional (minerals & vitamin C) and anti-nutritional (oxalate & phytate) contents of Solanum scabrum (SS) and S. villosum (SV). Three methods of drying namely indirect solar drying (ISD), mixed solar drying (MSD), and open sun drying (OSD) were employed. Furthermore, blanching (85°C, 2 min) with and without 3% salt (NaCl) were used as pre-treatments for ANS. The effect of pre-treatment methods on nutrient retention and anti-nutrients removal was also recorded. From the results ISD was the most effective method for vitamin C (14.76% 19.2%), Ca (92.90%, 96.57%), Fe (77.88%, 71.54%), and Zn (86.94%, 90.09%) retention for both SS and SV leaves, respectively. On the other hand, all drying methods significantly reduced levels of oxalate (4.46% to 35.24% ) and phytate (52.12% to 85.55%). Pannelists rated dried ANS significantly ≤ 0.05 higher for texture, colour, taste, aroma, bitterness and overall acceptability. Shelf life studies of dried products were stable at ambient and refrigeration storage for a period of three months with no growth of bacteria, yeast and mold, with significance loss of Vitamin C under both conditions. The findings showed that the ISD best method for vitamin C, minerals retention and anti-nutritional reduction.
Effect of drying methods on the nutritional and anti-nutritional quality of African nightshade (Solanum sp.)
(INNSPUB, 2022-08-25) Kazosi, Marynurce; Martin, Haikael; Matemu, Athanasia
African nightshade (ANS) is a luminary food plant, considered a cheap and potential dietary source for micronutrients and bioactive compounds. This study evaluated the effects of drying techniques on nutritional (minerals & vitamin C) and anti-nutritional (oxalates & phytate) contents of Solanum scabrum (SS) and S. villosum (SV). The study employed three methods of drying; indirect solar drying (ISD), mixed solar drying (MSD), and open sun drying (OSD). Furthermore, blanching (85 °C, 2 min) with and without 3% NaCl were used as pre-treatments. Results showed that the ISD method retained more vitamin C in a range of 14.76% - 19.2% in both SS and SV leaves. The ISD was the most effective method in Ca (92.90%, 96.57%), Fe (77.88%, 71.54%), and Zn (86.94%, 90.09%) retention for both SS and SV leaves, respectively. On the other hand, all drying methods significantly reduced the oxalate and phytate content. The effect of pre-treatment methods on nutrient retention and anti-nutrients remaoval was also recorded. Results showed that ISD to be the best method for vitamin C and minerals retention and anti-nutrient reduction. Therefore, ISD can be a suitable method for preserving ANS while retaining nutrients and reducing anti-nutrients.
Trends and constraints in the utilization of African nightshade (Solanum nigrum complex) in Tanzania: A case study of Kilimanjaro and Morogoro regions
(African Journal of Food, Agriculture, Nutrition and Development, 2022-08) Sangija, Frank; Kazosi, Marynurce; Martin, M; Matemu, Athanasia
African nightshade (ANS, Solanum nigrum complex) is among the most widely distributed and consumed indigenous vegetables in Tanzania. Several challenges hamper the utilization of ANS. This study sought to assess trends and constraints to ANS utilization in Kilimanjaro and Morogoro regions, Tanzania. Quantitative and qualitative methods were employed to collect information on ANS production, processing, and postharvest handling. Semi-structured questionnaires were used to collect quantitative data, whereas focus group discussion (FGDs) was used to collect qualitative data. A total of 627 farmers participated to fill questionnaire, and about eight FGDs with 6 - 10 participants conducted in Kilimanjaro and Morogoro. The results showed that 72.1% of farmers grow different ANS species, with Solanum scabrum vastly cultivated. Also, 79.4% of ANS farmers use irrigation, handheld hoe (97.6%), pesticides (70.7%), and fertilizer (64.8%) to produce ANS. African nightshade is mainly used as food (96.1%), animal feed (41.3%), and medicine (38%). On average, only 5% of ANS sales contributed to family income. Findings show that the main constraints to ANS utilization were pests and diseases (92.9%), lack of knowledge (58%), fertilizer shortages (51%), shortages of pesticides (50%), inadequate means of transport (50.4%), lack of extension services (48%), improper postharvest handling (41.4%) and inadequate storage facilities (34%). Postharvest losses accounted for 78.4% loss of ANS. Mitigation measures were; harvesting in small quantities (54.5%) and instant selling (61.9%) of fresh ANS. Drying (5.3%) and fermentation (1.1%) were the minimal value addition methods for ANS preservation. Moreover, boiling (63.0%) and frying (45.4%) were the typical methods of cooking ANS. More emphasis should be placed on good agricultural practices, providing knowledge to farmers, and supporting access to agricultural inputs such as pesticides, fertilizers, and quality seeds. Furthermore, knowledge of the processing and preservation of ANS is necessary for farmers to improve utilization, reduce losses, and ensure ANS availability. Also, research should focus on breeding local cultivar, which is resistant to pests and diseases.