Analysis of the quality of liquid smoke coconut shells using Technoher equipment

Many food industry products require preservatives to extend their shelf life. Natural preservatives are a necessity for safe food products. One natural preservative can be made from coconut shells. Liquid smoke from coconut shells is produced using liquid smoke pyrolysis equipment which has been developed by authors called Technoher. This study aimed to compare physical and chemical properties of various grades of liquid smoke from coconut shells produced using Technoher equipment, and study the specific applications of liquid smoke based on the grades. To produce the expected quality (3 grades), 3 treatments are made. The results showed that Grade 1 (G1) specifically the G1+ treatment sample had the lowest PAH value of 0.00 µg/g, while the G1 had a value of 0.007 µg/g. Grade 2 consisting of G2 and G2+ treatments, yielded PAH values of 0.002 µg/g, and 0.006 µg/g respectively, while Grade 3, produced a value of 0.026 µg/g. Based on the results, the three grades of Coconut liquid smoke were within the tolerance limit for PAH (Benzo (a) pyrene). The products contain no toxic substances and are safe, with Grades 1 and 2 are food grade, while Grade 3 has the potential for non-food preservation (non-food grade).


Introduction
The healthcare and global food industries are currently faced with significant challenges.Many health and food products, both in solid and liquid forms, may contain Benzo(a)pyrene, a carcinogenic compound, resulting from incomplete combustion during processing.The maximum limits set by the Food and Agriculture Organization/World Health Organization (FAO/WHO) are 12 μg/kg and 10 µg/L for non-liquid/solid and liquid products respectively.Consequently, when individuals inhale or consume these products as food or beverages, carcinogenic compounds unknowingly enter the body, potentially triggering the growth of cancerous cells [1].Food, solid and liquid such as fish, meat, and processed products may contain high levels of antimicrobial and antioxidant compounds.These antimicrobial compounds inhibit the growth of spoilage bacteria and pathogenic bacteria, which are the main causes of diseases in the human body.The antimicrobial properties, specifically antibacterial are highly effective in killing and inhibiting the growth of certain bacteria and fungi [2] Liquid smoke is the result of condensation of steam from indirect combustion which comes from some natural raw materials such as coconut shells [3].Coconut shells may serve as a preservation for both food and non-food products including wood and furniture.It can also be used as a natural fertilizer and pesticide for plants or an effective odor neutralizer in warehouses and farming [4] and [5].The three grades of liquid smoke have not yet been produced in large quantities or commercialized in the national and international markets.This is primarily due to the lack of comprehensive quality testing and analysis, specifically for the presence of toxic or hazardous substances that can potentially cause diseases in the human body.One of the critical parameters to be analyzed is Benzo(a)pyrene, a carcinogenic compound formed due to incomplete combustion of organic compounds during processing.Carcinogenic substances, being invisible, can exist unnoticed and enter the body through various means, including the air, food, and beverages [6] and [7].
Liquid smoke must have chemical content that is safe for human consumption.These include low levels of polycyclic aromatic hydrocarbons (PAHs), which can be dangerous if consumed in large amounts.PAHs are a byproduct of the combustion process and must be maintained at safe levels in accordance with food health standards.Therefore, appropriate processing and tools including clean, clear, and safe must be prepared.There needs to be a quality filter and an aroma that is not annoying.This is closely related to attention to environmental and health aspects.This is very important to convince the public that natural preservatives are safe and can produce sustainable activities to optimize the natural potential of Indonesian coconut shells.
This study aimed to ( 1) analyze the quality of various levels or grades of coconut shell liquid smoke produced by the modified Technoher equipment, and (2) determine the specific applications of liquid smoke based on the grade level.The benefit of this research is to obtain results of the performance of Technoher equipment and assess the level of safety and health of the liquid smoke produced which is suitable for food and other purposes.

Materials and tools
The materials used in this study were coconut shells, aluminum foil, distilled water, benzo(a)pyrene (pa), acetonitrile (pa), methanol (grade HPLC), anhydrous Na 2 SO 4 , and ethyl acetate.Meanwhile, the tools utilized included the Technoher equipment to produce liquid smoke, a set of HPLC instruments (Perkins Elmer-Series 200 specifications), measuring cups, analytical scales, refrigerators, centrifuges, rotary evaporators, chromameter (UltiMate 3000 RSLCnano) and microfilters.The analysis was carried out at the Laboratory Department of Food Science and Technology, IPB University, Bogor.

Study methods
This study used several methods including the Technoher equipment (figure 1) to produce liquid smoke, and to analyze the quality of coconut shell liquid smoke.High-Performance Chromatography (HPLC) was used to determine the PAH (Benzo (a) pyrene) values [8], PH Meter for PH levels, and Chromameter to analyse color.In this research, result categories were created based on the process to produce grade 1, grade 2 and grade 3. Therefore, for grade 1 and grade 2, tests were carried out on each of the 2 products (G1 and G1+, and G2 and G2+), because they require precision as are expected to be used for food preservation.

Description of the Modified Technoher equipment for Producing Coconut Shell Liquid Smoke
The structural design of the equipment was developed in simple and practical way.It was tested that the yield was 30%.It was also added 2 additional filters for filtration.The Technoher equipment was designed by the authors.This enables the pyrolysis process to be completed in 7-8 hours.The yield rate was 30% achieved by using 100 kg of coconut shell as raw material, producing 30 liters of grade 3 liquid smoke.
The structural and functional design of the Technoher liquid smoke equipment has a heat-resistant iron plate as a base, with simple dimensions, is easy to move, and is fuel-efficient, using coconut shell fuel.The Technoher equipment is the development of the previous equipment and in operation, this equipment model pays attention to control the average moisture content, uniformity of raw material sizes, and combustion temperature control [9] and [10].The Grade 3 liquid smoke was then subjected to a distillation process at temperatures ranging from 75°C to 90°C for approximately 3 hours.After distillation, the sample was immersed in a container filled with zeolite stones for about 4 hours.It was lifted and filtered using filter paper, resulting in Grade 2 liquid smoke (Figure 3).The Grade 2 liquid smoke was subjected to a second distillation process (fractional distillation) for approximately 3 hours.The sample was placed into a container containing activated charcoal for about 4 hours.It was then filtered using filter paper, resulting in Grade 1 liquid smoke (Figure 4).

PAH Test (Benzo (a) pyrene) Coconut Shell Liquid Smoke
Benzo (a) pyrene is one of the most carcinogenic polycyclic aromatic hydrocarbons affecting humans and is often used as a standard for assessing the presence of PAH compounds in food.Polycyclic aromatic hydrocarbons (PAH) can enter the human body through various routes, such as respiration or inhalation, absorption by skin pores, and ingestion through the consumption of food and beverages [7].
Carcinogenic compounds can be identified using PAH (Benzo(a)pyrene) in liquid or solid products that have undergone the pyrolysis process, consisting of incomplete combustion at specific temperatures.These compounds are invisible and trigger the growth of cancer cells, pose a threat to human health, and even harm the environmental ecosystem when the levels exceed the maximum limit in the body.Carcinogens, being imperceptible substances, can exist in the surroundings unnoticed and enter the body through various means, including the air, food, and beverages.
The results of the PAH (Polycyclic Aromatic Hydrocarbon) (Benzo (a) pyrene) coconut shell liquid smoke test for the three grade levels are shown in Table 1.Based on the results, Grade 1, specifically the G1+ treatment had no PAH (Benzo (a) pyrene) content, suggesting the absence of the carcinogenic compound.The value in G2+ was 0.006 µg/g, while the highest value of 0.026 µg /g was detected in Grade 3. Table 1 shows that the PAH value for coconut shell liquid smoke across all grade treatments ranged from 0.00 µg/g to 0.026 µg/g [5].These values fell within the normal range specified by the Food and Drug Monitoring Agency of Indonesia (BPOM RI), namely 10 µg/L for liquid products [1].Furthermore, the recommended maximum PAH values required by the Food and Agriculture Organization (FAO) and the World Health Organization (WHO) in non-liquid and liquid products are 12 µg/kg and 10 µg/ L respectively.This implied that all grades of coconut shell liquid smoke products were within safe limits and did not contain carcinogenic or toxic substances dangerous to health.Grades 1 and 2 were recommended as safe alternative natural preservatives for preserving food products including meat, fish, tofu, tempeh, and noodles.Meanwhile, Grade 3 was suggested for non-food preservation such as preserving wood, and furniture, deodorizing animal husbandry, fertilizer, and pesticides good for plants.The levels of benzo(a)pyrene produced by restaurants in Manado City exceeded the maximum limit set.
Natural preservatives are currently very important to increase food safety and shelf life [11,12].Things that needed to pay attention about natural preservative is the taste and aroma [13].Liquid smoke from coconut shells has been proven also to control pests naturally.It can reduce dependence on chemicals to control pests [14].

PH and Color Test of Coconut Shell Liquid Smoke
The PH and color test results of coconut shell liquid smoke products for the three grade levels are shown in Table 2. Table 2 shows that the highest PH value was found in the G1+ treatment at 4.75, followed by G2+ and Grade 3 at 4.62, and 2.90 respectively.Based on the color test performed using the Chromameter method, the lowest range of 1.85 was observed in G1+.This proved that the color of Grade 1 liquid smoke was very clear, according to its physical properties (Figure 1).Meanwhile, the highest color value of 122.80 was found in Grade 3, evidenced by the formation of a brownish color (Figure 4).The PH value and color indicated the quality of coco smoke, playing an important role in providing attractiveness, aroma, and showing the uniqueness of the product.

Table 2 .
PH Test Results and Color of Coconut Shell Liquid Smoke