Đề tài Improvement of export and domestic markets for Vietnamese fruit through improved post - Harvest and supply chain management

1 CARD PROJECT 050/04 VIE Improvement of export and domestic markets for Vietnamese fruit through improved post-harvest and supply chain management Fruit Quality Comparisons of Three Cat Hoa Loc Mango Supply Chains in Southern Vietnam By Robert Nissen1, Ms San Tram Anh2, Ms Tran Thi Kim Oanh2, Mr Vu Cong Khanh2 & Mr Ngo Van Binh2, 1 Queensland Department of Primary Industries and Fisheries (DPI&F) , Maroochy Research Station, PO Box 5083 SCMC, Queensland, Australia, 4560. 2 Southern Sub-Institute of Agricultural Engineering and Post-Harvest Technology (SIAEP), 54 Tran Khanh Du Street, District 1, Ho Chi Minh City, Vietnam. 2 FRUIT QUALITY COMPARISONS OF THREE CAT HOA LOC MANGO SUPPLY CHAINS IN SOUTHERN VIETNAM. Robert Nissen1, Ms San Tram Anh2, Ms Tran Thi Kim Oanh2, Mr Vu Cong Khanh2 & Mr Ngo Van Binh2, 1 Queensland Department of Primary Industries and Fisheries (DPI&F) , Maroochy Research Station, PO Box 5083 SCMC, Queensland, Australia, 4560. 2 Southern Sub-Institute of Agricultural Engineering and Post-Harvest Technology (SIAEP), 54 Tran Khanh Du Street, District 1, Ho Chi Minh City, Vietnam. INTRODUCTION In Southern Vietnam, traditional wet market supply chains for agricultural fresh food are now giving way to new supermarket-led supply chain systems. The rapid transformation in the fruit and vegetables sector is due to the meteoric rise of supermarkets, hypermarkets, superstores, neighborhood stores, convenience stores, discount stores in Southern Vietnam. This change is impacting on both the upstream and downstream agricultural food supply chain participants through demands for safe, high quality and sustainable-produced fresh products and the greatest impact is being felt by the small farmers of southern Vietnam. Problems with traditional procurement supply chain practices include low- or no product standards, supply inconsistencies, highly variable transaction costs and limited or sequestered market information. Supermarkets are now setting new procurement practices and supply systems which focus on reducing costs and improving quality to enable them to sell at lower prices. This will allow them to win over consumers and obtain a larger share of their target market. The ability of many small farmers, collectors and wholesalers in the Mekong Delta of Vietnam to meet safe food levels and quality demands of domestic and overseas supermarkets can only be obtained through investing in improvements in their production and supply chain practices. Implementation of new production and post–harvest practices and the modernisation of these supply chains may prevent some small farmers from participating. Many small farmers will have to develop risk minimisation strategies, such as forming groups, implementing new crop management and production systems, improved packaging, more efficient transport methods and handling practices to provide a safe, competitively priced quality product. Understanding how to develop new supply chains and where to make changes is essential if farmers and all chain participants are to benefit. This CARD Project set up experiments to evaluate the benefits of developing new improved supply chains for mango in Southern Vietnam with farmer groups. The Cat Hoa Loc Mango METHODOLOGY This CARD Project set up three different value/supply chains. This was done to demonstrate to the CARD project participants (farmers to retailers) the effects each supply chain product flows had on fruit quality. The mango variety “Cat Hoa Loc” was chosen as the variety to test and develop new value/supply chains for, as it’s highly regarded and sought after by Vietnamese consumers. Fruit assessments were carried out at the SIAEP laboratory in Ho Chi Minh City. After passing through each of the respected supply chains a 100 fruit sample was taken on two occasions, Experiment 1 on 14th May 2008 and Experiment 2 on 1st June 2008. 3 Two separate experiment times were set up to verify the results obtained from the three supply chains. SUPPLY CHAINS TRIALED Three different value/supply chains were trialed. These were: • Traditional supply chain (no change in technology or supply chain practices) • New supply chain (new improved pre- and post-harvest technologies) • Metro Cash and Carry cool supply chain (New improved pre- and post harvest technologies) Due to extreme difficulties in tracking the fruit from the wholesale markets to retailers in Ho Chi Minh City, it was decided that fruit samples be obtained when the fruit reached the wholesale markets in Ho Chi Minh City for the Traditional and New supply chains. Fruit samples for the Metro chain were obtained from Metro Cash and Carry Supermarkets after travelling the full length of the chain (See Figure 1, 2 and 3). TRADITIONAL AND NEW SUPPLY CHAIN MAPS For the Traditional and New Supply Chains without a cool chain component, a 100 fruit sample was collected from the Cat Hoa Loc Mango Cooperative, Tien Giang province in Vietnam and transported to SIAEP laboratory in Ho Chi Minh City by truck, whilst the rest of the fruit continued down the chain to the retail market and consumer. The sampled fruit was placed in a room at SIAEP laboratory, temperature 28-30oC, until ripe and then their quality assessed. 4 Figure 1. Traditional supply chain map. Farmer Harvests fruit on 16/4/2008 Cat Hoa Loc Mango cooperative Transport by motorbike Wholesaler HCMC Transport by Truck Bamboo basket Graded & pack in 35kg bamboo baskets Grade & pack in 35kg bamboo baskets and display for sale Transport by motorbike Retailer Consumer Sample taken on 18/4/2008 by SIAEP in HCMC 5 Figure 1. New supply chain map. Farmer harvests fruit with secateurs and leaves a long 20cm stem on 16/4/2008 Cat Hoa Loc Mango cooperative Transport by motorbike Wholesaler HCMC Transport by Truck Graded & pack in single layer fiberboard trays Transport by motorbike Retailer Consumer Fruit lowered carefully to ground and stems trimmed to 5-10mm in length and sap drained from upside down fruit Bamboo baskets used but only 3 fruit layers deep and each fruit separated by paper. Fruit sanitised, and treated for post- harvest diseases Sample taken on 18/4/2008 by SIAEP in HCMC 6 Figure 3. Metro supply chain map. METRO COOL SUPPLY CHAIN MAP For the Metro Cool Supply Chain fruit were transported from the pack house in Cai Be, Tien Giang Province by air conditioned van (20-25oC) to Metro warehouse where the fruit were temporary placed in the Metro warehouse cool room at 5-10oC for 6-8 hours. The fruit were then transported to the supermarkets by a cold truck before 6:00 am of the next day, and displayed for sale at 20-25oC. Fruits were collected from the supermarkets and placed in a cool room (20oC) at SIAEP laboratory until fruit ripened. Farmer harvests fruit with secateurs and leaves a long 20cm stem on 16/4/2008 Cat Hoa Loc Mango cooperative Transport by motorbike Metro HCMC warehouse & stored at 5-10oC for 6-8 hours Transport by air-conditioned Van at 20-25oC Graded & pack in single layer plastic trays Transport Metro cold truck to supermarkets Metro supermarkets and displayed at 20-25oC Consumer Fruit lowered carefully to ground and stems trimmed to 5-10mm in length and sap drained from upside down fruit Bamboo baskets used but only 3 fruit layers deep and each fruit separated by paper. Fruit sanitised, and treated for post- harvest diseases Sample taken on 18/4/200 by SIAEP in HCMC 7 HARVESTING PROCEDURES AND PROCESSES TRADITIONAL SUPPLY CHAIN Fruit were harvested in the traditional manner on the 16/4/2008. Fruit are plucked from the tree by hand or harvest stick and packed into rigid bamboo baskets. These fruit baskets are then transported to the collector residence by motorbike. Fruit are then graded according the wholesalers standards, placed in 35 kg rigid bamboo baskets for transport by truck to the wholesale markets in Ho Chi Minh and samples collected on the 18/4/2008. NEW AND METRO COOL CHAIN Fruit were harvested on the 16/4/2008 with a 20cm in length stalk either by cutting fruit from tree with secateurs or by hand and breaking fruit off leaving a long stalk. Fruit were then placed into small bamboo baskets lined with paper. Baskets of fruit were then gently lowered to the ground by rope. Fruit were then removed and the stalk length cut to about 7cm. Harvested fruit then had their stems cut to 5-10 mm in length, while being held upside-down. Fruit were then placed on paper on the ground in the shade of the tree canopy to allow the sap to drain. Once the sap had stopped oozing from the fruit, they were then packed gently into the rigid bamboo baskets with each fruit separated and baskets packed no higher than 3 layers deep and taken to the packing shed by motorbike. If fruit the stems were too long, they were re-cut at the packing shed to the correct length of 5-10mm. Once the fruit reached the packing shed, they were sanitised and washed in clean fresh water within 24 hours of harvesting. Fruit were graded by size and suspected immature fruit eliminated by flotation method. Fruit were then immersed in a 52oC clean hot water dip for 5 minutes to prevent fruit quality losses from post harvest diseases. Temperature was carefully controlled to within 0.5°C to prevent fruit damage. An accurate thermometer was used to monitor temperatures in various parts of the dipping tank. Fruit were then placed on sorting benches and fan dried, sorted and graded according to quality standards, then packed into single layer trays (fiberboard cartons) and transported overnight to the Metro Cash & Carry Retail market in Ho Chi Minh City were the 100 fruit samples were collected on the 18/4/2008 and taken to SIAEP laboratory. FRUIT MEASUREMENTS External quality measurements for Experiment 1 were carried out on storage days 1, 3, 5, 6, 8, 10, and for Experiment 2, storage days 2, 5, 10. All fruit sampled from each supply chain were from Class 1 grade. All internal fruit quality analysis was carried out once the fruit had ripened for both Experiments. Assessments undertaken were: • Average fruit weight in grams • percentage moisture loss over time • Skin colour (measurements taken using a Minolta Chromometer CR 200 and expressed as L a b values) • External quality measurements rated using the hedonic scale (1-9) o External fruit appearance o Visible area of external damage on the fruit:- Rub marks, abrasion damage, bruising or pressure marks and sapburn recorded. o Visible insect damage:- grub chew marks, thrip and mite damage etc. o Visible disease damage:- anthracnose damage area, stem end rot area, bacterial black spot and dendritic spot etc. • Internal quality measurements o Flesh colour (measurements taken using a Minolta Chromometer CR 200 and expressed as L a b values) o Sensory evaluation (taste, flavour and appearance ratings were based on the hedonic scale of 1 to 9. 8 o Firmness was measured by hand held Effegi Penetrometer FT 001 using an 11mm tip and force calculated as kg per cm2. o Titrateable Acid measured using 10g of flesh and added 100mL of double distilled water and macerated. This solution was then filtered through cotton wool and 10 mL of juice was collected and 2 drops of phenolphalayene indicator was added and titrated with Sodium Hydroxide (NaOH) 0.1 normal solution until colour change occurred. o Total soluble solids or degree Brix, was measured using a temperature compensation hand held Atago Refractometer Model N-1E. • Vitamin C content was measured using Association of Analytical Chemists (AOAC) International method 967.21. Procedure used was: • Take 10 gram of fruit flesh and grind with 5 mL Metaphosphoric-acetic solution. • Remove all sample and place into a 100mL flask and add Metaphosphoric-acetic solution until it reaches 100mL and shake. • Filter through absorbent cotton or rapid paper. • Take 10ml of the above solution and place into a 100mL glass beaker • Titrate this solution with 2,6 diclorophenol indophenolat natri until pink colour appears. This takes about 2 minutes to occur (note number ml = X). • Count amount of 2,6 DCPIP need to titrate 1mg acid ascorbic ƒ + Take 2mL standard acid ascorbic solution add 5mL Metaphosphoric-acetic ƒ +Titrate with 2,6 diclorophenol indophenolat natri until pink colour 2 minute (note number ml : y) • Titrate blank sample with 2,6 diclorophenol indophenolat natri until pink colour appears. This takes about 2 minutes to occur (note number ml = B) Calculation Content of Vitamin C = Pv VFBX . 100..).( − (mg/100gram sample) ƒ X: number of ml 2,6 diclorophenol indophenolat natri titrate sample ƒ V: extracting solution volume ( V = 100mL) ƒ v: extracting solution volume to titrate (v = 7mL) ƒ P: amount of sample ( p = 10g) ƒ F: number of mg ascorbic acid equivalent 1ml standard 2,6 diclorophenol indophenolat natri ( F= Y 2 ). • Taste evaluations were carried out by an expert panel established at SIAEP laboratory using the hedonic scale (1-9):- 1 = dislike very much 3 = dislike 5 = neither dislike or like 7 = like 9 = like very much RESULTS AVERAGE FRUIT WEIGHT There were no significant differences between the three chains based on fruit weight sampled on the 18/4/2008 plus one day. Table 1 below indicates the average fruit weight for each supply chain. 9 Table 1: Average fruit weight as of the 19/4/2008 Sample description Traditional Supply Chain average fruit wt (g) New Supply Chain average fruit wt (g) Metro Cool Supply Chain average fruit wt (g) Experiment 1 445.64 484.30 468.46 Experiment 2 448.39 434.78 440.90 FRUIT WEIGHT LOSS For the Traditional and New Supply Chains, the fruit weight rate loss was greater than the sampled fruit from the Metro Cool Supply Chain (Figures 4 and 5). Storage temperatures for the Traditional and New Supply Chains were similar. There were no significant differences between the Traditional and New Supply Chains for fruit weight loss over time for both Experiment 1 and Experiment 2 but when comparing the Metro Cool Supply Chain to the Traditional and New Supply Chains for Experiment 1, the weight loss rate was reduced by about 35% and for Experiment 2 the weight loss rate was reduced by about 61%. Therefore, keeping mango fruit cool down the supply chain significantly reduces fruit weight loss and extends shelf life by at least 2 to 3 days in the high humid temperature conditions in Southern Vietnam. The hot dip treatment of mango fruit to prevent post-harvest diseases did not appear to affect the fruit weight loss rate. Both the Traditional and New Supply Chains had similar fruit weight loss rates over time for Experiment 1 and 2, but the fruit weight loss for the Metro Cool Supply Chain was significantly slower for both Experiment 1 and 2 (Figure 4 and 5). Storage days +1 at 28-30oC after reaching wholesaler 0 2 4 6 8 10 12 W ei gh t l os s (% ) a fte r r ea ch in g w ho le sa le r 0 2 4 6 8 10 12 14 16 Traditional supply chain New supply chain Metro cool supply chain Figure 4. Comparison of the percentage of fruit weigh loss rate in for the Traditional, New and Metro Cool Supply Chains for Experiment 1. 10 Storage days +1 at 28-30oC after reaching wholesaler 0 2 4 6 8 10 12 W ei gh t l os s (% ) a fte r r ea ch in g w ho le sa le r 0 2 4 6 8 10 12 14 16 Traditional New Metro Figure 4. Comparison of the percentage of fruit weigh loss rate in for the Traditional, New and Metro Cool Supply Chains for Experiment 1. 11 COLOUR READINGS Minolta Chromameter CR 200 was used to determine skin colour changes of the sampled fruit. The colour space measurements are:- L* colour space (positive values indicate lightness and negative values indicate darkness), a* colour space (positive values indicate red hue as opposed to negative values indicate greenness), and b* colour space (positive values indicate yellow and negative values indicate blue). Figure 5. L* a* b* colour space difference ∆E* ab Lightness 25% Lightness 50% Lightness 75% Figure 5. Colour diagrammatic representation of L* a* b* colour space values Note: Colour show here may not be a true representation of colour observed by the naked eye as these colours patches are dependent computer, screen and printer settings used to display or print this report. 12 SKIN COLOUR READINGS By looking at skin colour from the different supply chains, we have we have tried to determinate the effects on freshness. Survey work conducted by the CARD Project 05004/ VIE found: • Wholesalers prefer to purchase mangoes with long stalks (>10cm) attached, this is a sign of freshness • Wholesaler also prefer to purchase mangoes that are light green all over in colour as this is a sign of freshness • Under high temperature and high humidity conditions, mangoes in Vietnam ripen very quickly and also breakdown quickly due to disease (anthracnose and stem end rots) • Mango fruit in Vietnam do not ripen evenly due to the high temperatures during the ripening phase (> 27oC) • Fruit are often force ripened in temperature above 35oC by wholesalers • Consumers in Vietnam prefer to eat Cat Hoa Loc mango fruit that have about 60 to 80% yellow skin colour and a 40% to 20% very light green skin colour • Consumers regard this green skin colour a sign of freshness EXPERIMENT 1 COLOUR SPACE READINGS Comparison of representative colour space patches of fruit samples taken from the Traditional Supply Chain, New Supply Chain and Metro Cool Supply Chain for Storage Day 1 and when fruit were classed as full ripe for Traditional Supply Chain – Storage Day 6, New Supply Chain – Storage Day 8 and Metro Cool Supply Chain – Storage Day 11 (Figures 6). 13 Tradition Supply Chain New Supply Chain Metro Cool Supply Chain Storage Day 1 (L* 57.58, a* -14.20, b* 33.20) Storage Day 1 (L*60.35, a* -15.77, b* 33.89) Storage Day 1 (L* 58.87, a* -16.21, b* 31.13) Storage Day 3 (L* 59.71, a* -13.89, b* 32.74) Storage Day 3 (L*62.21, a*-14.13, b*35.39) Storage Day 3 (L*6.38, a*-15.70, b*32.60) Storage Day 6 (L* 61.96, a* -8.70, b* 39.09) Storage Day 6 (L*64.37, a*-8.44, b*41.75) Storage Day 6 (L*62.70, a*-14.66, b*35.23) Storage Day 8 (L* 61.37, a* -8.16, b* 41.28) Storage Day 8 (L*64.42, a*-12.27, b*40.78) Storage Day 11 (L* 64.48, a* -2.97, b* 44.45) Figure 6. Comparison of representative colour space patches of fruit samples taken from the Traditional Supply Chain, New Supply Chain and Metro Cool Supply Chain for Experiment 1 Note: Colour show here may not be a true representation of colour observed by the naked eye as these colours patches are dependent computer, screen and printer settings used to display or print this report. 14 EXPERIMENT 2 COLOUR SPACE READINGS Comparison of representative colour space patches of fruit samples taken from the Traditional Supply Chain, New Supply Chain and Metro Cool Supply Chain for Storage Day 1 and when fruit were classed as full ripe for Traditional Supply Chain, New Supply Chain and Metro Cool Supply Chain – Storage Day 9 (Figure 7) Tradition Supply Chain New Supply Chain Metro Cool Supply Chain Storage Day 1 (L* 58.09, a* -16.73, b* 31.20) Storage Day 1 (L*58.90, a* -15.76, b* 31.55) Storage Day 1 (L* 58.87, a* -16.21, b* 31.13) Storage Day 5