High Post-harvest Losses Research Articles

Intra-household gender division of labour and decision-making on rice postharvest handling practices: A case of Eastern Uganda

AbstractGains in increasing productivity of grain in Sub-Saharan Africa are greatly undermined by the high postharvest losses (PHLs), which compromise the food and income security of households. Rice is one such important food and cash crop experiencing high PHLs. Given the limited mechanization of smallholder farms, PHLs result from practices influenced by knowledge, decision-making power in the household and cultural norms. Gender is an important consideration in the interaction of these factors especially for a duo purpose crop like rice serving both food and income security interests of households. A descriptive cross-sectional survey informed by qualitative focus group discussions was conducted in two major rice producing districts in Eastern Uganda to establish how gender division of labour and decision-making influence PHLs at the household level. The intra-household gender structure, division of labour and decision-making determine the postharvest loses of rice at the household level. Men and boys...

Physico-chemical and enzymatic changes in low temperature stored plum fruits in response to putrescine application

Plum is a perishable fruit and its ripening coincides with the hot and dry summer months under north Indianconditions. It has very short storage life at ambient temperature and high postharvest losses. An experiment wasplanned to extend the post-harvest life of plum fruits with putrescine application under cold storage conditions. Physiologically mature and uniform fruits of plum cv. Satluj Purple were dipped in different concentrations ofputrescine (0.0, 1.0, 2.0 and 3.0 mmol l−1) for 5 min. Treated fruits were air-dried in shade and packed in corrugatedfiber board boxes with paper lining before storage at 0–1˚C and 90–95% RH for 35 days. Results revealed thatfruits treated with putrescine @ 3.0 mmol l−1 retained the acceptable quality by reducing physiological loss inweight, spoilage, pectin methyl esterase activity and maintaining the fruit firmness, sensory quality, total solublesolids, titrable acidity, total sugars, reducing sugars and non-reducing sugars up to 28 days of storage.

Physical, Proximate and Functional Properties of Flour and Protein Isolate from Four γ-Irradiated Groundnut Cultivars

Contamination of groundnut seeds with microorganisms and insect’s results in high post-harvest losses of groundnut cultivars. γ-irradiation of groundnut could be a better alternative to chemical preservatives which have been implicated for their residual effect, environmental hazards and carcinogenicity. However, the effect of γ-irradiation at low to high doses on groundnut cultivars and their constituents has not been fully investigated. Four cultivars of groundnut (Arachis hypogeae) namely bororo-white, bororo-red, bororo-hausa and campala were γ-irradiated (2-10 kGy) using 60Co source. Non-and γ-irradiated groundnuts were defatted using solvent extraction method to oil obtain oil and flour. Protein was isolated by isoelectric precipitation method, and freeze-dried. Physical (colour (L*a*b*), chemical composition, physicochemical and functional properties of the sample were determined. Generally, the colour of the protein isolates of bororo-white (L*=39.16-56.00, a*=16.45-33.58, b*=14.20-22.69) were significantly lighter than bororo-red (L*=25.29-32.29, a*=24.29-33.42, b*=9.11-10.66), bororo-hausa (L*=34.60-46.28, a*=15.70- 24.58, b*=11.36-17.97) and campala (L*=37.44-51.52, a*=9.27-16.95, b*=8.21-12.59) varied with γ-irradiation doses. Protein and moisture contents of seeds, flours and isolates varied significantly with cultivars and γ-irradiation from 24.69% to 27.55% and 7.41% to 7.82%, and 38.22% to 56.47% and 9.31% to 12.65%, and 83.46% to 87.79% and 3.77% to 6.75%, respectively. Swelling power and solubility index of flours and isolates increased significantly with increased temperature, varied with γ-irradiation and cultivars. γ-irradiation had no apparent effect on WAC and OAC; however, WAC and OAC of the protein isolates were significantly lower than flours. γ-irradiation, up to 10 kGy, had no deleterious effect on physico-chemical and functional properties of the groundnuts cultivars and their constituents.

Determination of vegetable postharvest loss in the last-mile supply chain in Tanzania: a lean perspective

Global population growth constrains the food supply chains. Consequently, this calls for serious efforts in minimising food wastes. Fresh vegetables are perishable in nature hence more vulnerable to postharvest losses (PHLs). This paper aims at determining PHLs experienced and establish the most prone channel for high PHLs. This study employed a case study strategy. Five popular vegetable markets were studied in Arusha City. Analytical methods were used to determine PHL both in terms of quantity and value as well as the profitability achieved by last-mile traders using tomatoes, carrots and cabbage as selected vegetables. Findings show that more PHLs occur at the retail stage and is more than twice compared to the amount at the wholesale stage. Cabbage exhibited the lowest turnover rate followed by carrots and tomatoes. Similarly, cabbage registered the highest PHL rate followed by tomato and carrots. On average, wholesalers cum retailers registered a PHL rate of about three times those of wholesalers per se. Retailers constituted 70% of respondents who acknowledged to have faced PHL. It was also found that, the longer is the chain the more PHL was sustained. The vegetable PHLs in Tanzania have remained understudied, and this study tried to cover this gap in the academia.

Determination of vegetable postharvest loss in the last-mile supply chain in Tanzania: a lean perspective

Global population growth constrains the food supply chains. Consequently, this calls for serious efforts in minimising food wastes. Fresh vegetables are perishable in nature hence more vulnerable to postharvest losses (PHLs). This paper aims at determining PHLs experienced and establish the most prone channel for high PHLs. This study employed a case study strategy. Five popular vegetable markets were studied in Arusha City. Analytical methods were used to determine PHL both in terms of quantity and value as well as the profitability achieved by last-mile traders using tomatoes, carrots and cabbage as selected vegetables. Findings show that more PHLs occur at the retail stage and is more than twice compared to the amount at the wholesale stage. Cabbage exhibited the lowest turnover rate followed by carrots and tomatoes. Similarly, cabbage registered the highest PHL rate followed by tomato and carrots. On average, wholesalers cum retailers registered a PHL rate of about three times those of wholesalers per se. Retailers constituted 70% of respondents who acknowledged to have faced PHL. It was also found that, the longer is the chain the more PHL was sustained. The vegetable PHLs in Tanzania have remained understudied, and this study tried to cover this gap in the academia.

Nutritional deterioration of stored Zea mays L. along supply chain in southwestern Ethiopia: Implication for unseen dietary hunger

Maize plays a key role in household food security in southwestern Ethiopia, but its benefits have been negated by high post-harvest losses. Previous loss assessment and management studies have focused mainly on quantity losses. This study was therefore designed to assess nutritional quality losses of stored maize along the supply chain in Jimma Zone, southwestern Ethiopia. Three districts representing potential maize producers and different agro-ecological regimes for maize production were selected for analyses. Sample collection started at harvest and continued for six months at two-month intervals from 21 selected actors along the supply chain. The experiment was conducted for two seasons, and a total of 72 samples were collected during each season. Both nutritional and anti-nutritional analyses were carried out following the international standards of the Association of Official Analytical Chemists. Data were analysed using SAS software (version 9.2) using a general linear model (GLM). The result revealed that moisture content significantly decreases (P < 0.05) as storage duration increases under different actors and agro-ecological conditions. But, showed increment during the final months under farmers' storage conditions. In addition, moisture content at the loading stage was not optimal for safe storage. Crude protein, crude fat, carbohydrate, and calorific value content significantly decreased (P < 0.05) as the storage duration increased, but fibre, ash, and major mineral (Ca, Zn, and Fe) content increased significantly over the storage period. Phytate and tannin content varied with storage duration and agro-ecological setting. Storing maize under traditional conditions along the supply chain resulted in substantial quality losses. This has great implications for nutrition insecurity and unrecognized undernourishment in the society. Additionally, substantial increases in fibre content above the optimum have important effects on nutrient absorption. There is thus a need to develop and disseminate appropriate storage technologies that minimize quality loss in maize stores.

Effect of Packaging on Shelf-life and Lutein Content of Marigold (Tagetes erecta L.) Flowers.

African marigold (Tagetes erecta L.) flowers are highly valued for their ornamental appeal as well as medicinal properties. However, their short shelf lives cause high post-harvest loss and limit their export potential. The review of patents and research articles revealed that different types of packaging designs/materials have been successfully employed for extension of shelf lives of cut flowers. The current work focuses on designing of different packaging configurations and selection of best configuration for preservation of marigold cut flowers. Ten packaging configurations, composed of four different packaging materials i.e., low density polyethylene (LDPE), polyethylene terephthalate, glassine paper and cellophane paper, were designed. Each pack, consisting of 20 ± 1 g of marigold flowers along with non-packaged control set were stored at 23 ± 2°C, 80% R.H., in an environmental chamber and the flowers were evaluated for their sensory attributes, phytochemical characteristics and physicochemical parameters of senescence to determine their shelf lives. Flowers packed in LDPE bag showed highest shelf life of 8 days with a lead of 4 days compared to control (shelf life - 4 days). This study also established for the first time the phenomenon of carotenogenesis in marigold cut flowers with significantly (P<0.01) higher production of lutein in LDPE packaged flowers. LDPE pack was the best design among the ten package designs, in preserving lutein content of marigold flowers and extending their shelf lives. This economically viable packaging can not only boost the export potential of this ornamental flower, but also allow utilization of nutraceutical potency of lutein.

Physicochemical and Microbiological Post-Harvest Losses of Camel Milk Along the Camel Milk Value Chain in Isiolo, Kenya

Camel milk value chain experiences a lot of constrains which are likely to leads to high post-harvest losses due to physicochemical and microbiological changes. However, the magnitude of these quality and quantity losses have not been quantified. The objective of this study was to quantify these losses at different stages along the camel milk value chain. The study established the mean pH along the Isiolo value chain to range from 6.5 to 6.6 and did not show significant (p&gt;0.05) difference along the chain. The percentage lactic acid ranged from 1.63 to 2.07 and showed significant (p&lt;0.05) different along the chain. 3.57% and 4.76% of milk at delivered at bulking/cooling hub in Isiolo town and terminal market at Eastleighin Nairobi,respectively, failed alcohol test. Total viable count (TVC) showed the highest count along the chain (1.78x106 to 8.1x108) while Staphylococcus aureus showed the lowest count along the chain (1.3x104 to 2.0x106). Generally the microbial counts increased along the chain. This could be due to the longer withholding time of the milk at the various points along the chain. More milk was lost due to Total viable count standard than coliform counts standard, 100% of milk at the terminal Eastleigh market, Nairobi were rejected due to TVC while 92.5% rejected due to coliform counts. Camel milk value chain was therefore shown to be of poor microbiological quality which results to a lot of milk post-harvest losses.

Harnessing nitrous oxide in post-harvest management of fresh horticultural produce

High post-harvest losses in fresh horticultural produce and the increasing apprehensions among the consumers for harmful chemical residues have made it imperative for researchers to find safe, novel and natural techniques to achieve augmentation in shelf-life without having any detrimental influence on human health. Nitrous oxide, commonly known as “Laughing gas” is a naturally occurring colourless and non-flammable atmospheric gas. In the recent past, several researchers have documented that nitrous oxide gas inhibits ethylene production as well as action in freshly harvested fruits and vegetables. It also exhibits high potential in inhibiting fungal growth and decay, consequently reducing post-harvest losses due to diseases. Owing to its non-toxic nature, nitrous oxide can be potentially used to delay ripening and senescence of fresh horticultural produce during post-harvest storage and to assure food safety. In the present review, we have mainly focused on various effects of nitrous oxide on postharvest decay, ethylene biosynthesis and its action, respiration and other physico-chemical attributes of fruits and vegetables. Post-harvest application of nitrous oxide may open up various opportunities for its commercial use to prolong storage and marketability of fresh horticultural produce.

Physico-chemical and enzymatic changes in low temperature stored plum fruits in response to boric acid application

Physico-Chemical and Enzymatic Changes in Low Temperature Stored Plum Fruits in Response to Boric Acid Application Plum is a perishable fruit and its ripening coincides with the hot and dry summer months under north Indian conditions. It has very short storage life at ambient temperature and high post-harvest losses. Keeping in view, an experiment was planned to extend the post-harvest life of plum fruits with boric acid application under cold storage conditions. Physiologically mature and uniform fruits of plum cv. Satluj Purple were dipped in different solution concentrations of boric acid (1.0, 2.0 and 3.0% ) as well as distilled water (control) for 5 minutes. Treated fruits were air dried in shade and packed in corrugated fiber boxes with paper lining before storage at 0-1°C and 90-95% RH for 35 days. Results revealed that fruits treated with boric acid 3.0% retained the acceptable quality by reducing physiological loss in weight, spoilage, pectin methyl esterase activity and maintaining the fruit firmness, sensory quality, total soluble solids, titrable acidity, total sugars, reducing sugars and non-reducing sugars up to 28 days of storage...

Impact of ripening stage and drying on selected quality attributes of apple mango cubes and leathers

Apple mango is an improved cultivar that has been widely adopted by farmers in Kenya for use in the fresh market and processing. However, its production and consumption are adversely affected by high postharvest losses, which result from the perishable nature of the fruit, especially during glut periods. This is partly due to limited availability of information on alternative product use. The aim of this study was to evaluate the impact of ripening stage and drying on the physico-chemical quality and sensory acceptability of Apple mango fruit grown in the upper Athi River region of Kenya. Moisture, crude ash, crude fibre, titratable acidity, total soluble solids, colour, total carotenoids and ascorbic acid of the unripe and ripe fresh mangoes were determined. Subsequent experiments involved drying of ripe and unripe mango cubes (8mm) in a windy oven (at 60°C) and, in parallel, drying of ripe mango puree (mixed with sucrose-glucose solution, citric acid and pectin) in a windy oven at three different temperatures (50, 60 and 70C) which resulted in mango leathers. Analysis of total carotenoids, ascorbic acid content and colour was done for all dried samples, followed by sensory evaluation using the nine-point hedonic scale. The moisture content, crude ash and total soluble solids increased significantly (P&lt;0.05) with ripening while titratable acidity decreased significantly (P&lt;0.05). Ascorbic acid content decreased from 98.03 to 86.45 mg/100g with ripening while total carotenoids content approximately doubled from 768 to 1436 μg/100g. Drying resulted in high retention of total carotenoids, whereas, ascorbic acid content decreased. The mango samples became darker and redder in all cases. Dried mango cubes and leathers derived from ripe mangoes had higher scores in the sensory analysis compared to those obtained from unripe mangoes. In conclusion, the stage of ripening and drying technique employed are critical in determining the nutritional and sensory characteristics of dried Apple mango cubes and leathers. Drying Apple mango leathers at 60°C is the best method that can be adopted.

Traders’ Perceptions and Acceptability on Use of Linings for Improving Tomato Packaging in Wooden Crates

ABSTRACTIn Tanzania, tomato (Solanum lycopersicum L) postharvest losses are high due to perishability, lack of awareness and knowledge of postharvest handling techniques, and use of poor packaging materials. Reduction of the current high postharvest losses of tomato can contribute to ensuring food security and improving livelihoods of smallholder producers. Wooden crates serve as a major means of packaging material for transporting tomatoes in most parts of sub-Saharan Africa, including Tanzania. Wooden crates are tightly packed without being properly secured. Crates are often constructed from poor quality timber with rough interiors, resulting in bruising damage to tomatoes during transport. An assessment of how traders perceive postharvest handling practices with wooden crates combined with lining material and how tomato quality losses are affected was carried out in March–April 2014. Use of wooden crates with brown paper lining was more cost-effective at wholesaler and retailer levels. Wholesalers were willing to adopt wooden crates with brown paper lining provided that the net benefits are positive. Wholesalers were overly concerned that retailers would not buy wooden crates with paper lining because they can not visually appraise and evaluate produce through sides of crates for their marketing decisions. This may not necessarily be the case because most retailers buy tomatoes in packed plastic basins. There is a knowledge gap between wholesalers and retailers on acceptance of appropriate packaging materials. Proposed interventions that tend to maximize net benefits of the supply chain actors could reduce postharvest losses and make produce more available and affordable to consumers.

Food and nutrition security: challenges of post-harvest handling in Kenya.

Presently, close to 1 billion people suffer from hunger and food insecurity. Statistics in Kenya indicates that over 10 million people suffer from chronic food insecurity and poor nutrition, 2-4 million people require emergency food assistance at any given time with nearly 30 % of Kenya's children being undernourished, 35 % stunted while micro-nutrient deficiency is wide spread. Key among the challenges contributing to inadequate foods include lack of certified seeds, seasonal production (rain-fed), high post-harvest losses and wastages, poor transportation, low value additions which reduce their market competitiveness. The present paper examines some of the underlying causes for high food wastage experience in Kenya and the associated challenges in addressing these problems. The paper also provides an overview of some of the basic solutions that have been recommended by various stakeholders. However, in spite of the recent efforts made to mitigate food wastage, there is still an urgent need to address these gaps through participatory, innovative community based interventions that will create resilience to climate change and enhance livelihoods of smallholder farmers in diverse ecosystems.

Cassava (Manihot esculenta Crantz) and Yam (Dioscorea spp.) Crops and Their Derived Foodstuffs: Safety, Security and Nutritional Value

Cassava (Manihot esculenta Crantz) and yam (Dioscorea spp.) are tropical crops consumed by ca. 2 billion people and represent the main source of carbohydrate and energy for the approximately 700 million people living in the tropical and sub-tropical areas. They are a guarantee of food security for developing countries. The production of these crops and the transformation into food-derived commodities is increasing, it represents a profitable business and farmers generate substantial income from their market. However, there are some important concerns related to the food safety and food security. The high post-harvest losses, mainly for yam, the contamination by endogenous toxic compounds, mainly for cassava, and the contamination by external agents (such as micotoxins, pesticides, and heavy metal) represent a depletion of economic value and income. The loss in the raw crops or the impossibility to market the derived foodstuffs, due to incompliance with food regulations, can seriously limit all yam tubers and the cassava roots processors, from farmers to household, from small-medium to large enterprises. One of the greatest challenges to overcome those concerns is the transformation of traditional or indigenous processing methods into modern industrial operations, from the crop storage to the adequate package of each derived foodstuff.

English

&nbsp; Mango is a highly perishable fruit and high post-harvest losses occur in Africa. In order to address this problem, 4 concentrations of Aloe vera gel (AG) (0, 25, 50 and 75%) and chitosan (1%) were tested at two temperature levels (room temperature 15-22&deg;C and 13&deg;C) to determine their effect on the postharvest life of mango (var.&rsquo;Ngowe&rsquo;). The experimental design was a 5 by 2 factorial experiment embedded in a complete randomized design with three replications. Data were recorded on titratable acidity, fruit colour, ascorbic acid and anthracnose disease incidence. The results showed that at both temperatures 50 and 75% Aloe concentrations significantly increased the shelf life evidenced by reduced decrease in titratable acidity. Fruit colour and ascorbic acid were also maintained for longer periods in these treatments. Findings of this study demonstrate the potential of using Aloe vera gel at 50% as a coating for improved postharvest shelf life and maintaining quality of mango fruits hence reduced postharvest losses. &nbsp; Key words: Aloe vera gel, postharvest shelf life, mango.

English

Mango (Mangifera indica L.) is a popular and economically important tropical fruit throughout the world due to its excellent nutritional composition, eating and visual qualities. However, the fruit is highly perishable and as a result high post-harvest losses continue to be reported especially in Africa. In order to address this problem, four concentrations of Aloe vera (AG) (0, 25, 50 and 75%) and chitosan (1%) were tested at two temperature levels (room temperature and 13°C) to determine their effect on the postharvest life of mango (var.’ngowe’). The experimental design was a 5 by 2 factorial experiment embedded in a complete randomized design with three replications. Data were recorded on weight loss, pH and total soluble solids (TSS) among others. The results show that at both temperatures 50 and 75% aloe concentrations significantly increased the shelf life evidenced by reduced percentage weight loss. Fruit firmness and total soluble solids concentration and pH were also maintained for longer periods in these treatments. Findings of this study demonstrate the potential of using A. vera gel at 50% as a coating for improved postharvest shelf life and maintaining quality of mango fruits hence reduced postharvest losses. Key words: Aloe vera gel, postharvest shelf life, mango fruit quality.

Shallot Yield, Quality and Shelf-life as Affected by Nitrogen Fertilizer

Shallot (Allium cepa var ascalonicum Baker) can be a substitute where bulb onion (A. cepa L. var cepa) does not do well. However, production and productivity of shallot can be limited due to poor soil fertility; lack of improved production techniques; unimproved varieties, and high post-harvest losses. Farmers in northeastern Ethiopia rarely apply fertilizers to shallot. A field study was undertaken in that region in 2007/2008 to determine effects of nitrogen fertilizer on yield and shelf-life of shallot. Treatments were 0, 50, 100, and 150 kg·ha−1 N and cvs. ‘Huruta,’ ‘Negelle,’ ‘Dz-sht-68,’ and a local landrace. Application of 150 kg·ha−1 of N increased marketable and total bulb yields by 26% over the control. The highest and the lowest marketable bulb yields were for ‘Dz-sht-68’ and the local landrace, respectively. In storage nitrogen fertilization increased bulb weight loss in all cultivars, with weight loss being highest for the local landrace. Nitrogen fertilization at 150 kg·ha−1 N increased bulb rotting up to 79% over the control. Shallot shelf-life was of short duration. Application of 100 kg·ha−1 N was optimal for shallot bulb production without affecting bulb quality.

Effect of type of syrup and concentration on blackberry osmotic dehydration (Rubus glaucus benth)

The high post-harvest losses in Blackberry fruits can be diminished through the application of conservation techniques that reduce the water content of the product. In the present research the osmotic dehydration technique was used to reduce the moisture content of blackberry fruits (Rubus glaucus benth). Two types of syrup (sucrose and honey bees ) were used at three concentrations (60 , 65 and 70 °Brix) for a total of 6 treatments. Gain soluble solids was determined, percent weight Loss and humidity during osmotic dehydration for a time of 12 hours. The measurements were performed at intervals of 2 hours. For each of the parameters studied regression equations give with and the coefficient of determination top of 90 % were obtained. The results of the physical variables and sensory analysis after the process allowed to select the best treatment, which was the immersion of honey syrup 65 °Brix.

Sustaining Frafra Potato (Solenostemon rotundifolius Poir.) in the Food Chain; Current Opportunities in Ghana

Frafra potato (Solenostemon rotundifolius Poir.)is one underutilized crop species which is critical to improving food security in the Upper East and Upper West Regions of Ghana. Food dishes of Frafra potato (FP) are a delicacy particularly for children. The tubers have high marketing potential even compared with its counterpart, sweet potato. However, crop improvement programmes in FP have been slow leading to the current varieties being recycled for several decades. Research tools such asfield survey, focused group discussions and key informant interviews were employed to gather information on production practices, challenges and strategies to improve FP production and utilization. Information was generated from 10 focused group discussions and 270 respondents in 5 districts. Overall, FP is produced under rain-fed agriculture by less than 30% farmers on less than ¼hectare/farmer. In Bongo, Kongo and Bolgatanga environs, FP is cultivated by over 70% of households to supplement household food. Production is primarily planned for domestic consumption; contributing up to 20% of household food between Octoberto December. Consumer preference traits included tuber size, starch, low water content, taste and ease of peeling. Key problems identified were decreasing soil fertility, lack of improve varieties, labour-intensive operations, insect pests and high postharvest losses. Crop improvement should target high yielding cultivars, large tuber size, white and pink flesh and biofortification with micro-nutrients. Processing tubers into stable preservable products using low-cost roasting, dry-frying and solar dehydration methods should be evaluated. Dissemination of current improved technologies to increase productivity requires prompt attention by the Ministry of Food and Agriculture.

Conceptual Framework for Estimating Postharvest Losses in Food Supply Chains: the Case of Plantain Fruits in Nigeria

Postharvest losses which refer to the measurable quantitative and qualitative food losses in any agro-food supply chain account for significant amounts of food loss. Lack of consistent information on exact amount of losses and assessment methods further complicate the problems and makes solutions very difficult. Plantain also known as cooking banana is an important staple food and cash crop in Nigeria with observed high postharvest losses. The current study proposes a conceptual framework for directly estimating postharvest losses and identifying causative factors using a commodity system approach.