The proximate composition (ash, titratable acidity, crude fat, crude fibre, moisture and sugars), soluble solids, ascorbic acid, polyphenol oxidase activity, macro-nutrients and heavy metal contents of storage-ripened papaya (Carica papaya L.) fruits from Mbezi, Dar es Salaam, Tanzania were determined. The determinations were repeated for early, middle and late-season papaya fruits. The fruits were always harvested at the mature green stage and allowed to ripen during room temperature storage. The results showed that papaya fruits had high moisture content (>85.5%), low acidity ( 84.5 mg/100 gfw), moderate total sugars (>13.0%) and soluble solids (>12.9%) content. Early-season fruits had the highest polyphenol oxidase (PPO) activity while late-season fruits had the lowest PPO activity. During storage-ripening the PPO activity in the papaya fruit decreased. Of the determined macro-nutrients (Ca, K, Mg, Na), potassium content (420 mg/100 g-fw) was the highest. Heavy metals content was very low in the papaya fruits. Variations in moisture content, reducing sugars, total sugars, soluble solids, titratable acidity, ascorbic acid content and PPO activity were observed during the season and during the ripening period. Tanz. J. Sci. Vol 35 2009, 47-55

/pdf/physical-and-chemical-composition-of-storage-ripened-papaya-46x2jbtq4g.pdf

Physical and Chemical Composition of Storage-Ripened Papaya (Carica papaya L.) Fruits of Eastern Tanzania

Functional and antioxidant properties of mucilage extracted from the pods of eight okra accessions grown in Benishangul-Gumuz region, Western Ethiopia, were evaluated. This study had shown that the mucilage contents of the pods of eight okra accessions ranged from 1.25 to 3.45 g/100 g. Functional properties of the mucilage of okra pods varied significantly (p < .05) and had respective ranges of bulk density of 0.58-0.64 g/ml; water absorption capacity of 2.45-4.60 ml/g; oil absorption capacity of 0.02-3.64 ml/g; emulsifying capacity of 42.22%-74.45%; emulsion stability of 42.22%-74.45%; foaming capacity of 50.51%-62.50%, and foam stability of 36.04%-54.35%. Total phenolic and flavonoid contents of the mucilage of the pods of okra accessions ranged from 4.66 to 49.93 mg GAE/g and 8.18-18.72 mg CE/g, respectively. The effective concentration (EC 50) values (mg/ml) of mucilage of okra pods varied from 3.15 to 6.60 and 1.10 to 1.85 for DPPH scavenging and metal-chelating activity, respectively. The study revealed that the mucilage of the pods of okra accessions was found to exhibit good functional properties and can offer a great potential in various food systems. Particularly, mucilage of the pods from OPA#5 and OPA#7 had desirable water and oil absorption capacities, whereas the mucilage of accession OPA#1 and OPA#6 had high emulsifying and foaming properties. The results also demonstrated that okra pod mucilage had potential sources of natural antioxidant.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/fsn3.596

Indigenous Ethiopian okra (Abelmoschus esculentus) mucilage: A novel ingredient with functional and antioxidant properties.

The quality and storage life of fruits and vegetables may be seriously compromised within a few hours of harvest unless the crop has been cooled promptly to control deterioration. The major problem during storage is the change in the quality parameters of the produce especially the physical characteristics such as; the color, texture, and freshness in which the price sometimes depend on. In order to extend the shelf life, fruits and vegetables need to be properly stored. Proper storage means controlling both the temperature and relative humidity of the storage area. Although, refrigeration is very popular but it has been observed that several fruits and vegetables, for example banana, plantain, tomato etc. cannot be stored in the domestic refrigerator for a long period as they are susceptible to chilling injury. Apart from this, the epileptic power supply and low income of farmers in the rural communities’ makes refrigeration expensive. Evaporative cooling occurs when air, that is not too humid, passes over a wet surface; the faster the rate of evaporation the greater the cooling. The efficiency of an evaporative cooling structure depends on the humidity of the surrounding air. Therefore, this paper reviews the theory, advances, principles, methods of evaporative cooling, and also the optimum storage temperature, relative humidity and shelf life of fruits and vegetables. An Evaporative cooler reduces the storage temperature and also increases the relative humidity within the optimum level of the storage thereby keeping the fruits and vegetables fresh. It can be use for short term preservation after harvested. Thus, an evaporative cooling is a low cost technology for storage of fruits and vegetables. The Technology of evaporative cooling is cost effective and could be used to prolong the shelf-life of agricultural produce.

/pdf/evaporative-cooling-a-postharvest-technology-for-fruits-and-50wvnaqz3h.pdf

Evaporative Cooling: A Postharvest Technology for Fruits and Vegetables Preservation

This study extracted the mucilage from Corchorus olitorius L. to observe its chemical and functional properties and suggest its possible applications in various fields. Corchorus olitorius L. mucilage was isolated by hot water extraction. FT-IR and HPAEC-PAD were used to describe the chemical composition, and the functional properties and antioxidant activities of the mucilage were also examined. The mucilage was mainly composed of uronic acid (34.24%, w/w). The solubility was 79.48 ± 1.08% at 65 °C, the swelling index was 29.01 ± 2.54% at 25 °C, and the water-holding capacity and oil-binding capacity were 28.66 ± 1.48 and 8.423 ± 0.23 g/g, respectively. The mucilage viscosity increased from 4.38 to 154.97 cP in a concentration-dependent manner. Increasing the concentration decreased the emulsion activity and increased the emulsion stability, most likely because of the corresponding increase in surface tension and viscosity. Results from antioxidant assays confirmed that the in-vitro radical scavenging activity of the mucilage increased with concentration. This study shows that C. olitorius L. can be utilized as a new hydrocolloid source, with potential applications in fields ranging from foods to cosmetics and pharmaceuticals.

/pdf/characterization-antioxidant-activities-and-functional-16cmekbp.pdf

Characterization, Antioxidant Activities, and Functional Properties of Mucilage Extracted from Corchorus olitorius L.

Post-harvest losses of fruits and vegetables in developing countries are mostly as a result of in proper storage facilities. While refrigerated cool-stores are the best method of preserving fruits and vegetables, they are expensive to buy and run. Consequently, in developing countries there is an interest in simple low-cost alternatives, many of which depends on evaporative cooling, which is simple and does not require any external power supply. Evaporative cooling occurs when air, that is not too humid, passes over a wet surface; the faster the rate of evaporation the greater the cooling. The efficiency of an evaporative cooling structure depends on the humidity of the surrounding air. Therefore, this paper reviews the concept, principles and methods of evaporative cooling for the preservation of fruits and vegetables. The evaporative cooling structures has prospect for use for short term preservation of fruits and vegetables after harvested. It reduces the storage temperature and also increases the relative humidity within the optimum level of the storage thereby helps in keeping the fruits and vegetables fresh.

Predicting Storability of Fruits and Vegetables in Passive Evaporative Cooling Structures

The storage of shea butter coated pawpaw carica papaya fruit at different storage temperature was investigated as regard the nutrients, sugars and minerals. Freshly harvested just ripe fruit of pawpaw carica papaya was coated with shea butter and stored at room temperature (27 C±1 C), refrigeration temperature o o (10 C±1 C)and freezing temperature (-5 C±1 C) for 8 days. The proximate, sugar (glucose, fructose and o o o o galactose) and minerals (Ca, Mg, Fe and Zn) were subsequently determined. The result of the study shows that the moisture content increases significantly (P<0.05) (85.25-95.25%) while other nutrients reduce significantly (P<0.05) in storage, the sugar and the minerals content also reduce significantly (P<0.05) in storage. The storage temperature of freezing temperature recorded the highest mineral content (Ca113.33mg/100g, Mg53.33mg/100g, Fe2.33mg/100g and Zn7.00mg/100g) at the end of the storage period which was significantly (P<0.05) higher than other storage temperatures. At the end of the storage period, there was no significant difference (P<0.05) in the glucose and fructose content of the pawpaw at the different storage temperatures.

Comparative Study of Quality Changes in Shea Butter Coated Pawpaw Carica papaya Fruit During Storage

Nutritional, phytoconstituent and antioxidant potential of mucilage extract of okra (Abelmoschus esculentus), water leaf (Talinum triangulare) and Jews mallow (Corchorus olitorius).

I. B. O. Dada

Papers

Comparative Study of Quality Changes in Shea Butter Coated Pawpaw Carica papaya Fruit During Storage

Nutritional, phytoconstituent and antioxidant potential of mucilage extract of okra (Abelmoschus esculentus), water leaf (Talinum triangulare) and Jews mallow (Corchorus olitorius).