Comparative study of chemical quality and sensory attributes of top brand cooking oils in Indonesia

. Cooking oil is one of the food products that are the basic needs of people in Indonesia. To maintain the quality of cooking oil, the government has issued a regulation that requires cooking oil to use in packaging. For four consecutive years (2019 – 2022), there have been three brands of packaged cooking oil with the highest Top Brand Index (TBI), namely A, B, and C brands. However, whether this is in line with chemical qualities and people's preferences regarding sensory attributes needs to be explored. The purpose of this study was to compare the chemical qualities of 3 cooking oils based on TBI and to find out the ranking of brands based on the sensory attributes of these cooking oils according to the people in Subang. It tested the quality of palm cooking oil based on SNI 7709:2019 with water and volatile matter, free fatty acid content, peroxide value, vitamin A, and pelican oil. Parameters in the ranking test are color, clarity, odor, and texture of packaged palm cooking oil. Order of TBI-based palm cooking oil brands according to chemical quality. The First Rank A brand has the lowest value of water content and volatile matter (0.028%), free fatty acids (0.009%) and peroxide value (0.1 Mek O2/kg), as well as vitamin A content (61.2 IU/g) and negative results for pelican oil. Ranking test results with respondents in Subang showed that the 1-3 brand ranks were C, B, and A-brands. The preference rating for cooking oil in Subang is inversely proportional to TBI and its chemical quality.


Introduction
Most Indonesians use cooking oil derived from palm oil.Indonesia's consumption of palm cooking oil per capita in 2020/2021 reached 15,275 tons, the highest above India, China, the European Union, and Pakistan [1].To maintain the quality of cooking oil consumed by the public, the government, through the Regulation of the Minister of Trade of the Republic of Indonesia Number 80/M-DAG/PER/10/2014, requires business actors who trade cooking oil to use packaging.These regulations impact competition in the packaged cooking oil industry, including competition between brands.Product brands can guarantee the quality of a product for consumers [2].The increase in palm oil prices in March 2022 impacted rising world palm oil prices.However, in the competition between packaged cooking oil brands for four consecutive years (2019 -2022), there are three packaged cooking oil brands with the highest Top Brand Index (TBI) [3], namely A, B, and C brands.
Indonesia's cooking oil trade data shows that the most significant percentage of the average data of the cooking trade margin ratio by West Java at 21.64 % [4].Subang was chosen as the research location because it has a Food Expectancy Pattern (PPH) value that tends to increase yearly, even more significantly than the PPH value of West Java Province-cooking oil [5].
Even though the top brand index has determined the three best brands in Indonesia, can they represent the quality of chemicals?Although there have been many studies that explain that packaged cooking oil has better quality than bulk cooking oil.Therefore, not all packaged cooking oil meets SNI's quality requirements [6,7].However, sometimes people need to learn the quality of good cooking oil seen from its chemical properties.The choice of cooking oil for consumption is sometimes due to the reputation of the cooking oil brand or from sensory observation.People choose cooking oil based on their favorite and familiar brands [8].In addition to the unknown chemical quality, Subang people's perception of the sensory quality of cooking oil also needs to be explored into how they perceive the sensory attributes of the top 3 brands of palm cooking oil in Indonesia.Therefore, testing the quality of packaged cooking oil from the three highest Top Brand Index is important.This study aims to (1) determine the chemical quality of the top 3 brands of cooking oil, (2) know the sensory assessment in the form of ranking the top three cooking oil brands, and (3) compare the results of chemical testing and sensory assessment results.

Material and method
Chemical quality testing was carried out at the Chemical Laboratory of the Politeknik Negeri Subang and Balai Besar Industri Agro (BBIA).The research sample used was the top 3 brands based on TBI, namely A, B, and C palm cooking oil brands.They tested the chemical quality of palm cooking oil based on SNI 7709:2019 [9], which consists of water content and volatile matter, free fatty acid, peroxide number, vitamin A, and pelican oil.Sample preparation for chemical tests was carried out according to SNI, and each parameter will be tested three times per sample.
The sensory ranking test consists of color, clarity, aroma, and texture attributes.The ranking test that will be carried out on samples of palm cooking oil packaging aims to see the order of brand ranking according to consumers.The ranking test can sort two or more samples according to intensity and preference.The way to show the ranking based on the assessment is with the first order being the highest sense and the subsequent order expressing improvement [10].The location of survey research was carried out in the Subang area with 120 ranking test panelists.

Chemical quality analysis of cooking oil
Cooking oil is one of the agricultural products consumed by the people of Indonesia, which must have a good quality value.The main composition of palm cooking oil is triglycerides that have gone through a fractionation process and contain vitamin A and provitamin A [11].The Indonesian state has set quality standards for palm cooking oil circulating in the market.This quality standard is the basis for comparing cooking oil tests carried out.Table 1 shows the results of the analysis of the chemical quality of the three top cooking oil brands in Indonesia.
The test results show that all brands have met the requirements of SNI.However, from a numerical point of view, there is a slight difference in the quality values of the three brands.Based on the test, the A brand has the best quality with the smallest values on water content and volatile matter, free fatty acids, and peroxide number.In addition, A brand oil has the highest total vitamin A content.As for pelican oil, it has negative results on all brands.The water content and volatile matter were the first chemical quality parameters to be measured.The oil's high-water content indicates the oil's low purity, consisting mainly of triglycerides.The presence of water content in cooking oil should be avoided because it can cause a hydrolysis reaction that can form Free fatty acids [12,13].Based on SNI 7709:2019, the maximum water content is 0.1 % mass fraction, and the three brands meet these requirements, where A brand has the lowest value, followed by B and C brands.However, the high-water content increases the oil hydrolysis during frying [12], which causes a rancid taste and odor in cooking oil.
Based on SNI 7709:2019, the maximum free fatty acid content is 0.3% mass fraction, where the three brands have met the requirements, with the lowest free fatty acid value being A brand, followed by B and C brands.The higher the free fatty acids in cooking oil, the lower its quality.The high value of fatty acid content is caused by a hydrolysis reaction that breaks down triglycerides into free fatty acids and glycerol.A high FFA value also indicates the content of DAG and MAG, which can increase the turbidity of the oil at low-temperature storage [14].The low value of free fatty acid levels in cooking oil indicates good oil quality, where the triglyceride bonds have not been broken, so the amount of free fatty acids is not much.
Peroxide value can identify the oxidation that occurs in fatty oils.The peroxide value (PV) measures the extent to which rancidity reaction occurs during storage [12,[14][15][16].Therefore, the peroxide number is one of the determinants of the quality of cooking oil.The test results show that the peroxide numbers of three brands are very far from the maximum peroxide value of SNI 7709:2019.Peroxide value in A and C brands was 0.1 mek O2/Kg, followed by B was 0.2 mek O2/Kg.This shallow peroxide value indicates that the quality of the cooking oil of the three brands is still excellent.The peroxide value correlates with the cooking oil's free fatty acid content.The levels of free fatty acids and unsaturated fatty acids oil react with oxygen to form peroxides [12][13][14][15].
The first reason is the oil's compatibility with vitamin A. Vitamin A is fat soluble, so it is easy to incorporate into the oil.Carotenoids, an essential part of cooking oil, α, and β-carotene, are the precursor vitamin A [11,17,18].Vitamin A in palm cooking oil is at least 45 IU/g [9].The top three cooking oil brands show vitamin A content exceeding the threshold.Although slightly different, the brand with the highest vitamin A value was the B brand, followed by A and C brands.
Pelican oil is non-saponifiable mineral oil.Therefore, pelican oil can indicate cooking oil adulteration.The scarcity of palm cooking oil in Indonesia in February-March 2022 can trigger cooking oil counterfeiting.The form of counterfeiting can be in the form of mixing cooking oil with non-food oil.Therefore, a qualitative test was conducted on pelican oil to ensure that the three packaged cooking oils used as samples were not fake.the top three brands meet the requirements according to SNI [9], all cooking oil used as food is negative for pelican oil.

Cooking oil ranking test
Based on Top Brands [3], the ranking test assesses the people in Subang's sensory attributes of cooking oil.One hundred twenty respondents from various regions in Subang ranked the sensory attributes of cooking oil, consisting of color, clarity, aroma, and texture.The results of data processing using ANOVA showed that the brand had a significant effect on all sensory attributes.Figure 1 shows the results of the cooking oil ranking test in Subang.Figure 1 shows that the C brand has the highest average value on all attributes.Brand C cooking oil ranks 1st, followed by brand B in second place and brand A in third place, on all sensory attributes, according to Subang people.The ranking test determines which products are most favored by consumers, the primary purpose of product marketing [10].
The role of color in cooking oil marketing is crucial because consumers generally use color parameters to indicate the quality of cooking oil.Although, in general, the color of the top three cooking oil brands is golden yellow, panellists prefer the color of the C brand because, in their view [2,19], the C brand has a lighter yellow color than the B and A brands.In addition, the bright yellow color gives the impression of better oil quality in the eyes of the people of Subang.People prefer clear cooking oil compared to cloudy or dark cooking oil.Although visually, the top three cooking oil brands have almost the same clarity, the people of Subang prefer the clarity of the C brand cooking oil, followed by B brand, and finally, A brand.Lighter colors also influence this clarity value, and panellists consider lighter colors to show high clarity.The palm oil bleaching process aims to eliminate carotenoids [18], the primary source of color pigments in palm oil.In the deacidification process, carotenoids degrade thermally, so most of the tocopherols and tocotrienols will be lost [12,18].
Aroma is the aroma of food products which is a response when volatile compounds from the food enter the nasal cavity-furthermore perceived by the olfactory system [10].Aroma is essential in the food industry because it can improve the taste and attractiveness of food products [20].Therefore, the people of Subang tend to like the smell of the C brand, The aroma of the three cooking oils is no different because they have been deodorized in palm oil refining [14,18].
The texture of a food product includes the viscosity used for liquids, solid products, and semi-solid products [21].Viscosity is one of the most critical parameters for determining the quality and stability of the food system [14].The results were like the previous finding: viscosity decreased with an increase in PUFA [16].Viscosity is one of the essential parameters required to determine the quality and stability of the food system  [14].The texture ranking results for the three top brands consist of C brand at rank one, B brand at rank two, and A brand at rank three, according to the people of Subang.The panellist revealed that C has a lower viscosity, so it feels smooth when touched [22].

Comparison of chemical quality and cooking oil rank test in Subang people
Measurements of chemical quality and brand ranking by the people of Subang have obtained the results shown in Table 1 and Figure 1.Subang was chosen as the research location intentionally (purposive) because it has a Food Expectation Pattern (PPH) score, which tends to increase every year, even more significantly than the West Java Province PPH score [5].Subang has a Gini index of 0.3 which is in a condition of moderate inequality [5].This condition shows consumption patterns and perception patterns that are not much different.The chemical quality analysis shows that the order of the Top brands based on TBI follows the quality of the chemical.The A brand has the highest chemical quality compared to the other two brands.Different from the perception of sensory quality according to the people of Subang, where all the highest sensory attributes are in the C brand, the third top brand based on TBI [22].
Subang people tend to like C cooking oil because it has a lighter color which also affects the perception of clarity.The people of Subang believe packaged cooking oil with a light-yellow color has a high vitamin A content and does not contain cholesterol [22].Most consumers prefer clear and light-yellow colors [8,14,23].Bleaching in the CPO refining process and the reduction of carotenoid pigments in cooking oil affect the clarity of palm cooking oil.Palm oil is obtained from the mesocarp of the fruit of the oil palm tree, which is naturally red due to its high beta-carotene content [12,13,18].Therefore, the fading of the red color in the oil indicates the reduced content of carotene in the cooking oil.The total vitamin A content is the calculated amount of vitamin A (HPLC) and vitamin A equivalent to carotene.This statement follows the results of the total vitamin A test, where C has a vitamin A content of 58.6 IU/gram, the lowest compared to other brands.
The sensory attribute of aroma is influenced by the content of free fatty acids and peroxides in cooking oil.The physical purification process of CPO aims to remove free fatty acids, color, and odor from the oil [14,18].The low content of free fatty acids and peroxides in the three brands of cooking oil causes the aroma assessment to be insignificant.Free fatty acids are formed due to the hydrolysis reaction caused by the water content in the oil.The higher the water content, the higher the hydrolysis reaction, which causes the free fatty acid levels to be high.Oxidized free fatty acids will form peroxide compounds [13,14,18].The high peroxide content will affect the aroma due to rancidity [12,18].

Conclusion
The order of TBI-based packaged palm cooking oil follows the order of its chemical quality.The First Rank A brand has the lowest value of water content and volatile matter (0.028%), free fatty acids (0.009%) and peroxide value (0.1 Mek O2/kg), as well as vitamin A content (61.2 IU/g) and negative results for pelican oil.The cooking oil ranking results showed that the 1-3 brand ranks were C, B, and A. Therefore, the preference rating for cooking oil in Subang is inversely proportional to TBI and its chemical quality.

Table 1 .
Chemical quality analysis of cooking oil.