GARLIC VALUE ADDITION

Introduction

Garlic (Allium sativum) is a vegetable species that belongs to the amaryllis family (Amaryllidaceae). It falls in the same genius with onions, shallots, leeks, rakkyo and chives. Garlic species are used both as food and medicinal herbs. Garlic’s bulb or head contains 4 to 20 pungent bulblets. The main varieties of garlic are softneck (Allium sativum var. sativum) and hardneck (Allium sativum var. ophioscorodon). Softneck is the main commercial variety with numerous bulblets.

The popularity of garlic around the world due to the spicy flavour (Puranik et al., 2012). The pungent flavour of fresh garlic results from a chemical reaction that occurs when the clove cells are broken and release both the enzyme alliinase and the compound alliin (Nichols, 2015). Aliin is converted to alicin responsible for the garlic’s flavour (Bhandari, 2012). The enzyme alliinase is heat sensitive and thus destroyed on cooking. Garlic varieties with purple or red colour papery skin have a rich flavour.

Garlic is nutritive containing contents of calcium, phosphorous, selenium, vitamin C, manganese and vitamin B6. Additionally, the gloves are known to have a wide variety of medicinal properties that are helpful in the cure of high blood pressure, respiratory problems, lowering blood cholesterol, among others. Garlic has also been shown to have a high antidiabetic, hypocholesterolemic, anti-hypertensive, anti-protozoa (plasmodium Spp), antiviral (Influenza A and B viruses), anti-parasitic (Entamoeba spp) and neuroprotective properties (Bisen and Emerald, 2016). Value-added garlic products like spices and supplements present several health benefits.

Garlic is among the most used spices and medicinal plants all over the world. Most of its health benefits are attributed to a group of compounds known as allicins. These allicin compounds contribute to the antioxidant properties of garlic and garlic preparations. These have a prevention action against lung cancer and cancers of the digestive system. Allicins also reduce the cases of atherosclerosis through protein modification and through inhibition of uptake of low-density lipoproteins. Allicins also have antimicrobial properties, working against most bacteria, molds and viruses. It is on this basis that garlic and its derivatives are used to treat colds and coughs as well as asthma and Bronchitis.

Multiple ways can be used in value addition of harvested garlic. Apart from the health benefits, value addition of garlic presents multiple benefits such as to boosting income from farm produce and availing garlic in off-seasons and thus regulating the market price.

 

Hardneck garlic

3.1 Cleaning

Once the garlic is harvested, it should be cleaned to get rid of surface microorganisms, soil and moisture that can cause rotting. Cleaning involves removal of the roots, leaves and the most outer dirty wrappers.  There is a need for careful cleaning to avoid bruising the cloves to prevent the entry of microorganisms that cause quality deterioration. Additionally, the papery layers should be left out, and the dirtiest part only removed because the papery skin is important for garlic protection and keeping the garlic fresh. For the hardnecks, you should trim the top and leave enough step to allow easy cracking.

The clean bulbs should be stored in a cool, well-aerated environment in clean ventilated bags or horticultural boxes to avoid sprouting.

 

3.2 Removal of inedible parts

Garlic contains a papery skin that should be removed by pressing firmly on the garlic with a flat side of the knife until the cloves loosen. Alternatively, the garlic can be pressed firmly on a cutting board or press using the heel of your hands to loosen the cloves and break the skin. After cracking, the papery layer is easy to remove. When removing the outer layer, there is a need to take care not to damage the surface of the clove (Puranik et al., 2012). After this process, you can place the cloves in a jar or metal bowl and shake for about 30 seconds to pull off the skin from the cloves or do skin removal using your hands.

Garlic with inedible parts removed.

3.3 Size-reduction

Disintegration/value reduction is done to reduce the size of garlic, mainly by cutting. Garlic chopping is done by use of a sharp knife on a chopping board where individual cloves are sliced to a desired size and shape. A garlic puree is made by use of a garlic press or uses a garlic crusher if in need of finely chopped garlic. Size reduction before thermal processes increases the efficiency of heat transfer for effective processing.

Garlic chopping using a knife

4.0 Principles and Methods of Value Addition

Value addition technology is effective in producing a variety of value-added garlic products. Any procedure done to make products be of more value and more desirable to the consumers is a method of value addition. There are numerous benefits from garlic value addition, including the following.

1. Value addition increases the income obtained from garlic produce.
2. Value addition business presents employment opportunities to many people involved in any of the value addition processes.
3. Value-added products are made available throughout the year, including garlic off-seasons.
4. Most of the processed products have high shelf-life.
5. Garlic processing reduces post-harvest losses.

 

4.1 Preservation and methods that can be utilized

Garlic can be preserved for several months while maintaining its quality. The softneck varieties can be stored up to 9 months when kept at commercial storage conditions at a temperature of 32°F (0°C). They can stay for one to two months when stored at 68° to 86°F (20° to 30°C). Hardneck varieties store for up to 6 months at ideal conditions.

It is not ideal storing garlic at a refrigerator of 40°F, or 4°C as this temperature stimulates garlic sprouting. Optimum conditions for garlic storage is a cool, dry and well-aerated environment. Storage at cool (60°F, or 16°C), dry, dark conditions will keep garlic for 3 to 6 months. Garlic's quality deteriorates on sprouting even though it's not poisonous. The cloves can still be cut, and the green part removed if there is a need to consume.

The methods of garlic preservation include the following.

i.Drying

Drying is a common method of garlic preservation. It is aimed at reducing the water activity in fresh garlic and prevent the chances of sprouting. Drying is a crucial step before manufacturing of garlic dehydrated products to reduce energy consumption. This method can be achieved through open sun drying, solar drying, oven drying, hot air drying, infra-red drying and fluidized bed drying. Quality problems associated with drying include flavour reduction and poor rehydration attributes of dried garlic. In open sun drying system, the product being dried is spread into a thin layer and exposed to direct sunlight. It is required that the humidity in the air be low. This method is cheap but has several disadvantages such as contamination by dust, dirt and atmospheric pollution; rodents and insect damage; poor drying rate; longer drying time; and microbial contamination. Solar drying uses heat energy from the sun which is concentrated on a plate collector and this energy is used to evaporate the water from the food matrix. This has advantages over the open sun drying system in that the humidity of heating air is reduced, contamination is minimized, heating time is reduced and the final product quality is higher. Solar drying is one of the most effective preservation methods for spices. It has the advantage of not only increasing the shelf-life of products, but also more improved color and nutritional quality compared to other drying methods. If the product is well prepared and the right parameters maintained during drying, a safe storage moisture content of 10-15% can be achieved in solar drying.

 

ii.Freezing

Garlic freezing can be done after preparation of garlic in certain ways. It can be chopped and wrapped in a plastic freezer bag. Alternatively, garlic bulbs, either peeled or unpeeled, can be placed in a plastic freezer bag. Garlic cloves can also be peeled and pureed with oil and the purée kept in an airtight container for blast freezing. The mixture should be immediately placed in a freezer to prevent the growth of Clostridium botulinum at room temperature.

 

iii.Refrigeration

Garlic can be dipped in undiluted wine or vinegar to provide an acidic environment before refrigeration. The acidic environment is ensured to prevent the growth of Clostridium botulinum responsible for producing deadly toxins that cause botulism characterized by blurred vision, speech and breathing difficulties and progressive paralysis (Nichols, 2015). This mixture can be stored for about 4 months. Longer storage can result in mould formation and disappearance of flavour. Any indication of moulds in the wine/vinegar mixture is hazardous, and the mixture is unfit for consumption.

 

iv.Storing garlic in oil

Peeled garlic can be dipped in oil and stored in a freezer for several months. The mixture can only stay in the refrigerator for up to 4 days. Garlic is low-acidic and therefore the garlic in oil mixture is unsafe to be stored at room temperature as it supports the growth of Clostridium botulinum. The low acidity, anaerobic and warm environment favours the growth of Clostridium botulinum (Abo et al., 2014). It is therefore recommended to immediately upon preparation take the mixture to the freezer.

Commercial garlic in oil products must be mixed with citric or phosphoric acid to raise acidity levels and render more safety (Harris, 2016).

5.0 Value Adding Technologies         

 

5.1 Vegetable Processing Technologies

Vegetable processing is gaining importance due to its role in quality preservation and extending the shelf-life of perishable vegetables . Garlic is a bulbous vegetable that is semi-perishable. Inadequate storage and transportation facilities lead to nearly 30% wastage of the crop. Several processes involved in vegetable processing are such as grading, washing, peeling, size reduction, freezing, dehydration and canning.

Garlic processing technologies provide an opportunity for value addition with dehydration being the main method of garlic value addition. Dehydrated flakes and garlic powder are the major value-added garlic products for export.

 

5.2 Value-added products from Garlic

Value-added products from garlic include dehydrated garlic flakes, garlic powder, garlic jelly, garlic insecticides, garlic vinegar, garlic pesto sauce, pickled garlic and braided garlic (Gorrepati & Khade, 2020).

 

1.Dehydrated Flakes

Dehydration removes available water that favours microbial activity (Singh, 2014). Dehydrated flakes have a long shelf life due to the minimized undesirable chemical and physical activities during storage. Garlic flakes are prepared by selecting quality garlic before processing. The hard, dry, membranous outer parts of the onion and garlic are removed manually. The outer membrane of garlic is scrapped off using a knife. The garlic bulbs are then washed in clean water followed by disinfecting in chlorine solution and finally rinsing in another batch of clean water. They are then peeled, cut, pre-treated and dryied in any suitable drying technique as highlighted in the drying sections above.

Dehydrated flakes

 

 

 

Steps for preparation of dehydrated flakes

 

Process flow for garlic dehydration

 

 

                                                                   

2.Garlic Powder

Garlic powder is made by grinding the dehydrated flakes using an attrition or hammer milling system into fine powder. The powder is mainly used for cooking purposes like in preparation of baked products, soups and flavouring grilled products. Garlic powder is hygroscopic, and thus proper packaging is needed. Some agents can also be added to prevent moisture absorption and allow long storage duration. Garlic powder is a popular ingredient in spice blends and dry rubs. It's used to season meat and vegetables, and proves a welcome addition in snacks like popcorn and roasted nuts. Garlic powder can even be used to get brighter flavors in low-sodium dishes.

Garlic powder

 

3.Garlic Pickle

Pickle is made by the addition of either vinegar or oil to the garlic. Oil-based pickles require the addition of other desired spicing agents and pH regulators to provide an acidic environment of pH less than 4 to render an environment that does not favour microbial activity upon long storage.

Garlic pickle

 

4.Garlic Oil

Garlic oil is made by extraction using complex steaming and distillation process. Garlic oil can be used as a flavouring agent, preservative or in medicinal purposes. Garlic has been used for blood vessel disease (atherosclerosis) and high blood pressure (hypertension). Some herbal/dietary supplement products have been found to contain possibly harmful impurities/additives.

Garlic oil

5.Garlic Paste

Garlic paste is made peeling and grinding the garlic to a paste. The paste is then treated either with preservatives or through thermal treatment to allow for long storage duration without microbial damage. Proper packaging is also required to store the paste for a long duration.

Garlic Paste

 

6.Minimally processed garlic

Minimally processed garlic is made by peeling and cutting of garlic to minimize the time taken in preparation and cooking of garlic. Garlic preparation can be done manually, but mechanical processing is preferred for commercial needs due to large quantities involved. The minimally processed products have a short life span; hence, proper packaging is involved in maintaining the quality of the products. Refrigeration of minimally processed garlic can also be done for a short duration.

 

Minimally processed garlic

 

7.Roasted Garlic

Roasted garlic as a sweet flavour and is used as a flavouring ingredient. It can also be used as a vegetable side dish or used as an appetizer on bread or crackers. Roasted garlic can be processed easily by roasting in an oven for about 40-45 minutes at 50-60 ^OC, or until the heads of garlic are tender, aromatic and caramelized. Roasting is showed to reduce the pungency due to allicin in garlic.

Roasted Garlic

 

6.0 Introduction to Product Quality Assurance         

A garlic processing firm can ensure quality control using the following quality control measures:

1. There must be specifications for the garlic to be processed.
2. The product should meet the specified standards, and proper packaging needs to be done.
3. There is a need for a specified production procedure that fits the regulatory requirements.
4. Avail a quality control system that governs all the production procedures and the final quality of garlic products.

 

6.1 Food safety and Standards for Garlic Processing

Food safety is a key consideration when storing vegetables because they have low acidity and can be a source of the hazardous Clostridium botulinum. Garlic is one of the low-acid vegetables and is therefore susceptible to Clostridium botulinum bacteria growth (Abo et al., 2014). This organism is found in water, air and soil. It does well in an oil environment with anaerobic conditions. Therefore, garlic in oil mixtures needs extra precautions with regards to storage to avoid the growth of Clostridium botulinum. The garlic-in-oil mixtures for commercial purposes are acidified to prevent bacterial growth. The mixtures are best stored when frozen to stay for longer durations. Refrigeration is not suitable because harmful bacteria can grow faster in higher refrigeration temperatures. If refrigeration is done, the mixtures should stay for only up to 4 days, after which the mixture is discarded or frozen to avoid spoilage. Raw garlic stored in vinegar can be stored at room temperatures. The stored products need to be labelled in the containers to show the preparation and the best before dates(C & Woodburn, 2015).

 

Important food safety measures in the garlic industry should include the following:

1. Install a food safety management system in place.
2. Adhere to good manufacturing practices (GMPs), including good hygiene practices (GHP) and good agricultural practices (GAP).
3. Control food hazards at all stages of the food chain. The main element of controlling food hazards is by implementing hazard analysis and critical control points (HACCP) principles.

 

6.2 Basic Characteristics of a Standard

• Define the required characteristics of products such as the maximum residue limits.
• Conform to similar fundamental requirements
• Displays guidelines for performing tasks
• Available and applied in all stages of food production.
• Defines the requirements of a management system, such as documentation requirements.

6.3 Importance of Standards

• Ensure the safety of products
• Protect health
• Promote international acceptance of products
• Helps in pointing out what is missing and builds on the existing strengths in the available systems
• Demonstrate conformance to international standards and applicable regulatory requirements.
• Reduces the risk of product liability claims  

7.0 Product Traceability

Traceability is the ability to discern, identify and follow the movement of a food or substance expected to be incorporated into a food, through all stages of production, processing and distribution ("Food Traceability Guidance", 2017).

Traceability is aimed at protecting consumers through faster and precise identification of a product under review. It is an important element of ensuring food safety and quality assurance. In case of any detected problem in a product, product recall, i.e. food safety or quality-based recall is done whereby food is removed from the market at any stage of the food chain. Food labelling display elements that can be important in the traceability process.

Record-keeping helps in storing useful information that links a final product to its ingredients and thus provides relevant traceability information.

It is important to assess if the traceability system is functioning as required regularly. Regular traceability updates are necessary to enable proper traceability functioning.

 

7.1 Components of a traceability system

The three basic components of a traceability system (The World Bank Group, 2019) include the following:

1. Product identification.
2. Information required to track the movement of the product/item through the supply chain.
3. Establishing a link between the product/item and the supply chain participant.

 

7.2 Minimum requirements for building a traceability system

1. Identification of the business food operator.
2. Identification of a traceable item and product labelling.
3. Record keeping that includes traceable information and copy of sales receipt for all transactions.
4. Chain of Custody of a traceable item should be identified. It should be linked to the flow of the traceable item to the information flow of that item and the recorded information.
5. Recall and withdrawal.

8.0 Equipment/processor Maintenance and Operation

Several types of equipment/processors have been developed for garlic processing. Some of the equipment, mainly used for commercial purposes, include size reduction mechanical slicers, garlic graders, garlic bulb breaker, garlic clove flaker, dry garlic peel remover and fresh garlic clove peeler (Prasad, 2020).  All the equipment, both for manual and mechanical use, need to maintained using the preventive, predictive and corrective maintenance.       

8.1 Preventive Maintenance

Preventive maintenance involves the equipment/processor care and servicing to maintain optimum operations through regular inspections and observations to detect and correct defaults before the occurrence of a total breakdown. It aims to extend the equipment/processor's life by predicting failures and is meant to promote safety and improve production. Preventive maintenance guarantees reliable and efficient performance of the equipment/processor and improves operation.

The seven basic preventive maintenance milestones include testing, servicing, calibration, inspection, adjustment, alignment and installation.

 

8.2 Predictive maintenance

Predictive maintenance involves determining the functioning of equipment to estimate when maintenance will be required. It is also known as condition-based maintenance and works by monitoring the equipment’s performance and condition during normal operation to reduce the chances of equipment failures. Condition-based maintenance predicts the likelihood of equipment failure at certain times, depending on some factors followed by preventing the failure through regularly scheduled and corrective maintenance. There must be continuous monitoring of equipment and production processes. The data is collected periodically on critical speeds and changing spindle positions. The importance of predictive maintenance is to allow accurate scheduling of corrective maintenance and prevent unexpected equipment failures.

 

8.3 Corrective Maintenance

Corrective maintenance involves repair or restoration of equipment that has failed in operation. This maintenance works by identifying the failure and rectifying the failure to bring back the equipment or to normal operation. It is important in rectifying the equipment to reinstate the equipment to normal operation and prioritize on tasks that may be safety-related or affecting production. The following are steps involved in corrective maintenance:

i.Confirmation of the detected failure.

ii.A confirmed equipment failure is prepared for maintenance and failure report done.

iii.Localization and isolation of a failed part in the assembly.

iv.Removal of the failed part for repair or disposal. If disposed of, a new part is acquired for installation.

v.After repair, reassemble, realign and adjust the equipment and return to use.    

9.0 Conclusion

Garlic is a valuable vegetable used in diverse culinary preparations due to its spicy flavour that offers fantastic taste in food and great health benefits. The diverse use of garlic and garlic products necessitates garlic processing, value addition and preservation to avail garlic products throughout the seasons and improve on the garlic’s quality and shelf-life.

Vegetable processing and preservation techniques are critical because of their high perishability and huge post-harvest losses encountered. Some of these techniques include blanching, canning, refrigeration and dehydration.

Food safety is important at all stages of the garlic value chain from production to consumption. There are set standards for achieving the quality standards during the value addition process that enhance achieving international set standards and regulatory requirements. Product traceability and equipment/processor maintenance are part of the food safety measures and quality control standards that should be established in the garlic value chain.

 

 

10.0 References

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8. Nichols, J. (2015). Stinking facts about garlic. MSU Extension. Retrieved 29 November 2020, from https://www.canr.msu.edu/news/stinking_facts_about_garlic.
9. Prasad, R. (2020). Technology Package of Garlic Processing for Value Addition. Rutag.iitd.ac.in. Retrieved 29 November 2020, from http://rutag.iitd.ac.in/rutag/?q=projects/garlic-processing.
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