K.Velmourougane, P.Panneerselvam, T. N. Gapinandhan,Y.Raghuramulu, D.R.Shanmukhappa, C.B.Prakasan and Jayarama

The quality has been defined as the "Totality of features and characteristics of a product or service that bears on its ability to satisfy the implied needs of the customer (ISO 8402-1986)" In the liberalized market scenario, quality assumes a paramount importance among the export oriented commodities like coffee. Quality of coffee, both visual and organoleptic is the cumulative contribution of various parameters. The intrinsic quality of coffee is established at the estate level apart from the internal and external factors viz., Altitude, chemical composition, bean size and density, age of plants, farm management, climatic conditions, defects etc. The processing techniques adopted at the estate level are the most important operation, which determines the quality of coffee beverage. In the present paper, the importance of Good Agricultural Practices (GAP), Good Manufacturing Practices (GMT), Good Hygienic Practices (GHQ) and Sanitary and Phyto-sanitary measures (STS) are discussed to improve the overall quality of coffee at on-farm level.

1. Harvesting

Generally in wet processing, two to three rounds of selective picking is practiced followed by main harvest and final striping, but in cherry preparation it is un economical for selective harvesting and hence stripping is followed (In cherry, harvesting the crop when more than 70% ripening is noticed may be followed for quality improvement). However the harvested coffee should be sorted out according to maturity categories before processing at least as greens and ripes for quality improvement. Coffee should be never allowed to tree dry as it encourages mould formation and inferior cup quality. It is always advised to use harvest mats to avoid direct fruit contact with soil and also to reduce the quantum of gleanings generated. Time lag between harvest and processing should be minimum i.e. below 4 hours since once the fruits are plucked from the plant it is susceptible for any microbial attack. The harvested fruits should be always stored in perforated bags under shade to avoid fruit fermentation within bags due to elevated temperature. Tree dried fruits (Moisture= 30-45%) and over ripe berries are highly susceptible to mould attack compared to sound fruits. Hence timely harvest is must to avoid quality spoilage.

Research findings: Higher mould incidence was recorded in gleanings, tree-dried and over-ripe fruits compared to ripe fruits. Though greens recorded lesser fungal contamination, the cup quality found to get reduced (Raw/Grassy taste). If the fruit lot contains different fruit maturity categories, the drying found to get affected due moisture differences in different fruit categories. Delay processing (Time lag between harvest and processing) found to increases mould incidence, spoils quality and increase mycotoxin production in coffee.

2. Sorting/Grading

It is difficult to pick only the ripe fruits during the main harvest, but the harvest lot can be segregated into different fruit maturity categories apart from removal of leaves and twigs from the coffee lot. Segregation of fruits before pulping

aids in easier and efficient pulping (avoids pulper cuts and fruit skin). Fruits may be graded into lots of two sizes by use of suitable sieve to minimize the pulper cuts. Grading of fruits before pulping found to reduce the pulper cuts in arabica.

3. Floatation Tank/Siphon Tank

The important component of wet processing is removal of floats including tree dried fruits by floatation tank before pulping which is not possible in cherry preparation. But as per three trials in coffee it was found that Prewashing of coffee before drying in case of cherry found to lower the mould infection during drying stage as well as on the final beans Research findings: Prewashing of cherries before pulping/drying found to reduce the quantum of mould on the surface of fruits compared to unwashed fruits in both arabica and robusta.

4. Pulping

Coffee fruits which are pulped generally will not be of same size, the result is higher pulper cuts in beans and more of skinned beans (due to higher green fruits). Hence it is always better to adjust the pulper discs and other components of pulper to suit the coffee (Varieties). During fermentation, the pulp/skin in the pulped beans contributes for darker colour (Tannins/Polyphenols) to the washed parchment apart from inviting un- wanted fungal community. In case of direct washing the fruit skin found to harbour more of harmful fungi as a result of high moisture and water activity during course of drying. The water used for pulping should be of good quality with less silt particles. Maintenance of cleanliness/hygienic is must in pulping section.

Research findings: Higher fruit injury in machine washed coffee and pulp contamination in fermenting beans (Even I%) found to invite more mould contamination and deteriorate the quality. Residues left un-attended in pulper section viz., un-cleaned fermentation vats, siphon tanks, carry baskets, fruit skins and pulp water found to harbour toxigenic mould and can re- infect the fresh coffee lot if conducive conditions exists.

5. Recycling of Water in Pulping Section

The recycling of water at pulping section should be restricted to one day and at any point of time the recycled water should not used more than two days as it deteriorates the coffee quality (Ferment taste/Foxy beans) apart from microbial contamination in the final beans. The recycled water should be used only for conveying of fruits to the pulper and it should be never used for washing/soaking. Research findings: Water recycled more than 2 days found to produce coffee with stinky smell and lower cup quality. Recycled water found to increase Pollution load (BOD, COD and Solids) of coffee effluent.

6. Demucilisation and Importance of Natural Fermentation in Coffee

Coffee demucilisation is done by several methods viz., natural fermentation, alkali wash, enzyme treatment, direct machine wash. Among these methods naturally fermented coffee is considered to be the washed coffee in the international market though the difference between fermented and machine washed coffee is not so wide. In India, alkali demucilisation (10 lits of 10% Sodium hydroxide/1200 kg pulped beans) of coffee is not widely followed now because of its nonecofriendly nature, but enzymatic method is followed widely with the commercial pectinolytic enzymes (Speedox 800g and Coffeezyme 2.6 lits/5000 kg fruits). Fermentation in coffee simply means the process concerned with the degradation/ removal of mucilage (a slippery layer, 1/2-2mm thick that surrounds the seed) by the combined action of naturally occurring enzymes in the coffee fruit and the growth of microorganisms. As per the study, it was found that dry fermentation found to be effective compared to under water fermentation.

Plantations which follow natural fermentation can improve their fermentation efficiency by: a) covering the fermenting mass by a plastic cover to conserve the temperature to hasten fermentation and to avoid flies b) stirring of coffee mass for proper and complete fermentation c) intermediate washing of beans in case of severe frothing d) inoculation of starter culture (Fermented liquor of previous batch). From recent study it was found that semi washed (Removal of coffee fruit skin and dried as such without washing) coffee produced cup quality in between washed and un washed coffee (Cherry coffee), the advantage of semi washed coffee is that, we can avoid pollution problem due to pulping/washing but the problem is that delivery of pulped fruits to drying yard and subsequent drying becomes difficult apart from the semi washed coffee invites more dusty materials which harbour more of fungal spores. Studies are under way to overcome the problem by use of dilute lime solutions.

India is one of the very few countries producing robusta parchment coffee; Indian robusta parchment has established a specific niche in the International market as one of finest robusta in the world. However, lack of proper fermentation and thorough washing has paved way for production of parchment with higher percentage of unwashed beans. Use of starter culture proves to hasten the fermentation process and complete removal of mucilage in robusta parchment preparation.

Fermentation of coffee apart from producing good cup, favours multiplication of wide variety of bacterial and yeast flora (Lactobacillus spp., Bacillus spp, Pseudomonas spp, Saccharomyces spp, Torula spp etc) which aids in flavour and aroma development during fermentation apart from inhibiting harmful fungal population which favours butyric or propionic acids (Over fermentation-Stinkers) and mycotoxins in final beans.

Fermentation tanks are made in brick masonry with smooth surface and a sloping floor (5%) running towards the outlet. The tanks should not be deeper than 1-1.2 Meters to ensure easy handling of coffee. A tank volume of 4.5m3 and 4.2m3 is required for pulped beans equivalent to a tonne of clean arabica and robust respectively (The depth of fermenting mass be maintained at 75 cm).

Research findings: fermenting coffee before washing found to reduce water quantity used for washing and fermenting beans found to reduce naked and skinned beans. Fermentation found to improve overall quality of coffee compared to machine washed. Fermented coffee recorded lesser mould incidence compared to nonfermented coffee.

7. Washing

Coffee washer should be prepared in such a way to assure complete removal of mucilage, since residual mucilage in parchment (if not soaked) tend to undergo fermentation during drying process lowering the quality to one side and invite undesirable mould incidence on other hand. Fermentation of coffee beans before washing found to reduce washing time, quantum of water used for washing and improve washing efficiency.

Research findings: Fermentation of coffee before washing found to reduce the washing time and water required fore washing and increase washing efficiency (Lesser nipped/ naked beans).

8. Post Wash Soaking

After fermentation / direct machine wash, coffee should be soaked under fresh water to improve coffee visual colour and appearance. During soaking the excess colour and bitterness producing compound like phenols and tannins are removed to give soft cup. Soaking of coffee beans apart from removing unwanted colour, it removes residual mucilage left after washing giving proper appearance to the final dried beans. There is a general suspicion that soaking of coffee will reduce the out turn weight and acidity of the cup, but studies are under way to confirm these parameters. As per three year trial, it was found that weight loss was more in naturally fermented coffee compared to machine washed. The reason behind this solid loss was due to more hours of soaking naturally fermented coffee compared to direct wash i.e. fermented coffee spends 12-15 hours on fermentation and another 6-8 hours on post wash soaking. But in machine washed coffee it has been restricted to only 6-8 hours. Hence it is wise to soak the fermented coffee for lesser period than machine washed coffee. For soaking 2700 kgs of washed wet parchment equivalent to one tonne of clean coffee, around 2000 litres of clean water and a tank of 2 M x 1.5 M x 1.2 M is required. Soaked coffee always produced better cup compared to unsoaked coffee Research findings: Post wash soaking of coffee recorded better quality compared to unsoaked coffee. The parchment quality found to improve due to removal of unwanted colouring material. Residual mucilage left after washing found to remove completely by soaking.

9. DRYING TECHNIQUES 9a. Tray Drying

Once the coffee is washed, it is advised to go for tray drying (Surface drying) to remove the excess moisture on the surface of coffee beans. Tray drying found to hasten the drying process in the main drying yard by removal of excess moisture and reduces splitting of parchment. A tray of 2 M (L) X 1 M (B) with 5 cm height can hold 2 forlit of parchment or cherry and the tray should be 75 cm above the ground level for easy handling.

Research findings: Tray drying before regular drying found to remove excess moisture in coffee and found to reduce one-two days of drying. Coffee which has been tray dried found to attract lesser dusty material compared to direct drying of coffee.

9b. Drying Yard

A perfect drying yard is a prerequisite for preparation of quality coffee since drying yard and drying practices could completely change the visual and cup characteristics of the coffee. The drying yard must be always located in elevated place of the farm where the maximum sun shine is expected and there should not be any risk of flooding and contamination by animals. A better drying yard may be concrete floor, tiled, brick stones, granite or any other hard surfaces. Coffee should be never dried on bare soil or soil smeared with cow dung slurry since these surfaces found to produce inferior coffee quality. Farms which do not have pucca drying yard facility may dry their coffee on plastic sheet or tarpaulin sheets (Picking mats) provided the coffee must be turned frequently to evaporate the condensed moisture in the bottom layer of plastic sheets (Impervious). The drying yard should be smooth with no crevices and cracks to get good coffee. The drying yard requirement for drying one tonne of clean coffee is 9.5 x 9.5 M for parchment coffee (4cm layer thickness) and 11 x 11 M for cherry coffee (7 cm thickness).

Research findings: From the study on comparison of drying floors for drying parchment and cherry coffee,it was found that soil and cow dung surfaces recorded higher mould and mycotoxin contamination apart from increasing days required for drying and lowered the cup quality compared to standard drying surfaces viz., concrete, tiled and tarpaulin surface.

9c. Thickness and Stirring Frequency

Generally the days required for drying parchment and cherry varies based the drying yard used, layer thickness, number of stirring/day, initial water content of the coffee, average sun shine hours at the site (Yard temperature and RH). As per coffee Board recommendations it is advised to dry parchment and cherry coffee to a layer thickness of 5cm and 8cm respectively, the thickness height can be increased as the coffee dries. Maintenance of correct layer thickness aids in faster and uniform drying, avoid splitting and casing of parchment and cherry respectively and avoid mould formation in coffee. Coffee should be raked / stirred at least 4-6 times a day for faster removal of moisture to avoid mould growth. The raking devices used should not be hard as it splits the parchment cover and may be provided with rubber beadings. Never mix fresh cherries with partially dried ones.

9d. ? 9d. Covering to Avoid Re-wetting

Covering of coffee is a regular practice in parchment preparation but it is not followed in cherry coffee due to practical problems. Parchment coffee lot with high moisture content should not be covered, but after it reaches a moisture of about 35% daily covering is necessary. Before covering coffee lots should be heaped and allowed for equilibration and then covered. If the lot is covered during hot sun, sweating of beans will re-wet the good lot.

Research findings: Rewetting of coffee lot particularly during later stage of drying (End of drying for desired moisture) found record more fungal incidence compared to initial stage of drying. Re-wetting coffee also found to increase drying days and bleaching of coffee during storage.

Heaping of coffee is generally followed in small and marginal plantations for following reasons a. Insufficient drying yard facility, b. Insufficient fruit quantity for spreading, c. Heaping of unsorted fruit aids in uniformity in ripening and d. Farmers believes that heaping hastens drying process. As per the research findings, it was found that heaping fruits for even one day may cause deterioration of coffee quality. The temperature in heaped lot found to increase steadily based on heap height and water content of fruits, which favours mould development and finally quality loss. As believed by farmers, heaping of coffee fruits found to reduce drying time by way of oozing out the internal contents of fruits (loss of moisture) but always produced poor cup quality and higher mycotoxin level.

Research findings: Heaping of coffee even for one day before processing found to seriously affect quality of final coffee. The mould incidence was found to be cent percent in all the heaped lots. The mycotoxin level found to increase as the heaping days gets increased. Drying days found to get reduced as the days of heaping increased.

10. Floats/Gleanings

In wet processing, the float coffee is generally removed by floatation method, but in dry coffee preparation this process is not done and the unsorted lot is dried as such resulting in higher mould incidence during drying as well as in final dried beans. Float coffee is generally weak coffee which is prone to higher colonization by mould during processing stage rather than on plant. Hence it essential to remove floats before processing. The best method to remove floats in cherry preparation is the Prewashing of fruits before drying. Prewashing of floats not only removes surface mould contamination but also reduced the mould load during drying courses. Gleanings on other hand are potential source of mould and mycotoxin contamination in coffee as the days of coffee contact with soil increases. Since soil is the reservoir of mould propgules, longer the fruit contact with soil more the contamination and quality loss. Gleanings should be collected in a shorter period and must be processed as separate lot.

Research findings: Floats found to record more fungal infection compared to normal ripe fruits. Removal of floats before pulping in parchment preparation (Floatation tank) and cherry preparation (Prewashing of fruits) found to reduce the total quantum of mould infection in final beans. Based on the simulation study on gleanings, it was found that mould load increases as the days of fruit contact with soil increased. The initial beneficial yeast population on fruit surface was displaced by toxigenic mould as the days of soil contact increases. Gleanings should be never mixed with good lot and must be dried and processed as separate lot.

11. On Farm Moisture Estimation

The most critical factor which decides the coffee quality as well its shelf life is bean moisture. Test weight method (Forlit weight), biting method and standard moisture meters are used for measuring coffee moisture. All the farms may not have moisture meters; hence the test weight method is much popular among planting community for moisture estimation. As per the research findings, there is wide variation in moisture content of final beans measured by test weight and moisture meters compared to standard oven dry method e.g. the test weight recommended for parchment is 15.5kg/forlit which approximately corresponds to bean moisture of 10.5%, but if we analyze the test sample of 15.5kg weight it shows bean moisture of 9% in once case and 11% in another study by oven dry method i.e. the coffee has been over dried and under dried respectively. The over and under dried coffee always produced inferior quality since in over drying we are losing coffee weight and quality (boat shaped beans, Woody taste), where as in under dried coffee the quality gets deteriorated by way of bleaching and mould infection. Hence it is better to use moisture meters for moisture estimation at on farm level. The moisture meter facility available at Extension centers and Research stations may be utilized for this purpose.

Research findings: there is a wide variation in moisture content of coffee beans measured by test weight methods and moisture meter compared to standard oven dry method. In general parchment found to over dry (Weight loss and woody taste) and cherry found to under dry (bleaching and mould incidence) if the coffee moisture is measured based on test weight method. Revalidation of test weight method used for moisture estimation at on I farm level is under way.

12. Winnowing .

This is the general practice followed in cherry preparation, where once the coffee reached desired moisture level will be winnowed before bagging. Winnowing not only improve the visual quality of coffee, but also removes the inactive and dry mould spores and dust/soil material from the lot. Dust contamination is found to be potential source of mould contamination in coffee, which cannot be avoided by any means during drying. Hence winnowing before bagging is the only option left to reduce the dust material in final stored coffee. If the coffee is not winnowed and stored, there is a higher chance of re-infection by mould species if they get sufficient moisture to grow under un-hygienic storage conditions.

Research findings: Air sampling during coffee winnowing recorded higher mould count apart from recording toxigenic mould in dust. Dust samples of gleanings and floats coffee recorded higher mould population compared to good coffee lot.

13. On Farm Storage

There should be clear demarcation between the different lots of raw coffee stored to maintain the identity of individual lots in respect to quantity and quality and the coffee stacks should not lean against walls of the godown. The stacks of raw coffee should be provided with dunnage made of parchment husk filled in gunny bags, while the clean coffee stacks should be provided with wooden dunnage. Both the raw and clean coffee godowns should be rodent proof and the materials like fertilizers, pesticides etc., should not be stored inside or near coffee godowns. It is always better to transport the coffee for curing before on set of monsoon.

The Floor area required for storing raw coffee (Uncured) equivalent to l tonne of clean coffee is 13.5 sq.ft when the wall height of the godown is 15 ft. In terms of volume the space required for storing raw coffee equivalent to 1 tonne of clean coffee is 202.5 cubic ft. The floor area required for storing 1 tonne of clean coffee is 7.5 sq.ft for a wall height of 14 ft. The optimum stack height recommended for raw coffee is 20 bags. In case the height of the godown is more than 15 ft., the stack height could be increased subject to a maximum of 24 bags equivalent to a height of 18 ft. In case of clean coffee, the maximum stack level prescribed is 14 bags Research findings: Coffee stored with high moisture (Under dried coffee) found to increase the mould incidence and gets bleached before it reaches curing unit, while overdried coffee found to produce inferior quality apart from weight loss.

14. Coffee Curing

In curing works, dust accumulation found to be the potential source of contamination in coffee. From a study carried at curing works during peak curing activity for dust settling rate, it was found that among curing machineries higher quantum of dust was generated by huller followed by polisher and the mould spores found to be more on polisher followed by de-stoner and huller. The historic dust (Dust accumulated over a period of time) was also found to harbour higher percentage of toxigenic mould. Hence proper facility should be provided in curing works to remove/avoid the dust particle settling on the curing machineries to avoid contamination by moulds and mycotoxin.

15. Coffee containerization and Shipment

Condensation occurs because moisture is always present in the air and hygroscopic materials such as coffee normally contain a certain amount of moisture as well. Containers must be technically impeccable: water tight; free of holes and free of corrosion on the roof or sides; intact door locks, rubber and sealing devices. They must always be swept clean and must be dry and odourless. When stuffing takes place at the shipper's premises the shipper must inspect the containers. If any daylight is visible the container must be rejected immediately by the inspector. The actual stuffing of the container should take place under cover, just in case of rain shower occurs during that time. Bags should be sound: no leaking, slack or torn bags; no wet bags; no stained bags. The saddle stow is the best way to stow bags in a container as it minimizes air circulation between the bags and so reduces transport of moisture to cold spots. Containers should never be filled to absolute capacity- always leave sufficient room above the stow. Best practice is to line the container with cardboard or two layers of Kraft paper, preferably corrugated, with the corrugation facing the steel structure. This will ensure that the paper will at least partly, absorb any condensation from the roof. Experience shows that most of the condensation problems encountered during maritime transport are caused at origin (Containers are stuffed too early ahead of actual shipment, or not properly lined), or immediately after offloading (particularly for containers arriving in winter). When making a booking with the carrier always give the instruction' stow away from heat, cool stow and sun/ weather protected'. The term `stow under deck' is no longer appropriate for modern containers vessels

16. Coffee Waste Management

Solid (Coffee pulp/skin) and liquid waste (Coffee waste water) are the major waste products of coffee processing. Solid wastes of coffee processing are not considered generally to be a waste or a major pollution problem due to its use as compost in coffee farms. On other hand the coffee waste water/effluent causes serious environmental pollution if allowed in ecosystem untreated. In composting also coffee wastes should be allowed for complete composting, or other wise the harmful mould which survives on the partially composted material found to enter coffee habitat where it contaminates the system. For coffee waste water, there is already proven method of treatment i.e. NEERI method/lagooning method (NEERI- National Environmental Engineering Research Institute, Nagpur) where 3 tanks especially neutralization, anaerobic and aerobic tanks are used to bring the pollution load of coffee effluent to the stipulated level before letting into environment. If the pucca NEERI tanks could not be constructed, atleast soil excavated lagoons may be used as alternative for treating coffee effluent. The main problem in waste water is removal of solids, which upon non-removal found to degrade faster by action of microbes resulting in lesser pH and higher pollution load (BOD, COD and Total Solids). Hence proper neutralization (Lime requirement = dg and 1.5g/ liter of arabica and robusta effluent respectively) of coffee effluent apart from neutralization aids in flocculation of solids to the surface of the water, where it can be removed.

Coffee Vs Price

The general claim by any planter is that "if we follow good hygienic and good manufacturing practices for production of quality coffee whether we will get better price compared to planters who are not following those steps". The answer for this is `yes'. Time has come to recognize the importance of quality coffee at internal and external market, but to reach the price fixing or to award premiums to better coffee, it may take some time. However the farms which feel their process and coffee is of better quality they may prove it by participating in cup tasting competitions or flavour of India context to explore their potential marketing. At present, Planters are ready to sacrifice quantity for quality and this is a good sign of total quality improvement in coffee production in India.

K. Velmourougane, Research Assistant Gr-I, Post Harvest Technology Lab, CRSS, Chettalli571 248, Coorg, Karnataka

P.Panneerselvam, Research Assistant Gr-II, Post Harvest Technology Division, CCRI, CRS577 117, Chikmagalur

TN.Gopinandhan, Research Assistant Gr-I, Analytical Lab, Coffee Board, Bangalore-1.

Y.Raghuramulu, Coffee Scientist (FAO Project), Analytical Lab, Coffee Board, Bangalore-1.

D.R.Shanmukhappa, Agricultural Chemist, Post Harvest Technology Division, CCRI, CRS-577 117, Chikmagalur

C.B.Prakasan, Deputy Director (Research), CRSS, Chettalli-571 248, Coorg, Karnataka Jayarama, Director of Research, CCRI, CRS-577 117, Chikmagalur

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