1 Analysis of factors affecting the quality of edible vegetable oil
1.1 Raw materials
Raw materials are the most important part of quality control in the production and processing of edible vegetable oil, and the quality of raw materials directly affects the quality of the final product. The main problems of edible vegetable oil in terms of raw materials are: (1) The raw material purchase verification is not in place. The raw materials used in the production and processing of edible vegetable oil are affected by soil, air, irrigation water, etc., and may contain heavy metal pollutants such as mercury, cadmium, lead, etc., as well as organic pollutants such as dioxins, polycyclic aromatic hydrocarbons, and polycyclic aromatic hydrocarbons. Chlorinated biphenyls and so on. Excessive use of chemical fertilizers, pesticides and herbicides in the cultivation process can easily lead to excessive residues of oily pesticides and biotoxins. In addition, oil has some mechanical impurities during harvesting and primary processing. These factors will bury hidden quality problems for the production and processing of edible vegetable oil. The "National Food Safety Standard Limits of Mycotoxins in Foods" (GB 2761-2017) sets the limits for aflatoxins, including peanut oil and corn oil at 20 μg/kg, and other vegetable oils at 10 μg/kg; “National Food Safety Standards” The Limit of Contaminants in Food (GB 2762-2017) has a limit of 0.1 mg/kg for total arsenic and 0.1 mg/kg for lead. It is especially necessary for the quality of raw materials to be inspected in accordance with relevant standards when entering the factory. According to the requirements of the "National Food Safety Standard and General Hygiene Code for Food Production" (GB 14881-2013), the purchase of food raw materials should check the product quality certification documents, which cannot be provided The food raw materials of the qualification certificate shall be inspected in accordance with the food safety standards, and the food raw materials must be checked and accepted before they can be used. In reality, some companies have not strictly inspected the quality certification documents of raw materials, nor have they conducted inspections in accordance with food safety standards; some have checked the quality certification documents, but due to the quality knowledge of the inspectors, the quality certification documents marked The batch does not correspond to the batch of the purchased raw material, which is an invalid quality certificate; when the raw material is inspected, due to the knowledge level of the enterprise equipment and the inspectors, the inspection items are incomplete and the inspection results are inaccurate; the enterprises without inspection conditions take into account the cost It does not entrust a qualified inspection agency to conduct inspections. (2) The storage of raw materials does not meet the requirements. Improper storage of oil will cause mildew and deterioration, resulting in low oil yield, increased acid value, and poor oil quality. The processed oil will have a deep color and smell. The raw materials must be stored in the factory under strict control of storage conditions. According to the requirements of the "National Food Safety Standard for the Production of Edible Vegetable Oil and its Products" (GB 8955-2016), the raw materials must be stored in categories, stored off the ground and off the wall, and the warehouse is ventilated and pest-proof. , Anti-rodent measures, the silos and storage tanks of bulk raw materials should be stored according to different varieties and different quality levels. During storage, temperature, moisture, and pests should be inspected and recorded, and kept away from harmful environments. In actual production, especially in some small and medium-sized enterprises, the storage of raw materials is chaotic and the classified storage fails to meet the requirements. For example, the warehouse does not have ventilation facilities, and the temperature and moisture control facilities are not in place. Natural ventilation is used for natural storage, and there is no regular inspection and recording. (3) Insufficient quality inspection measures for raw materials entering the factory. Some companies judge the quality level of raw materials based on subjective experience and lack technical measures. The survey found that 60% of small oil processing companies do not have inspection equipment, and 30% of medium-sized companies have incomplete inspection equipment and can only inspect some items. The quality of raw materials lacks scientific data support. A few companies use unqualified raw materials in order to reduce costs, so the quality of raw materials is difficult. Guarantee, bury hidden quality hazards for the production and processing of edible vegetable oil.
1.2 production and processing
The production and processing of edible vegetable oil is the key link of product safety. The main problems are as follows: (1) the influence of oil. In the process of planting, harvesting, threshing and drying, although oil plants have been cleaned up to varying degrees, due to the limitation of technical conditions, various inorganic and organic impurities still remain, such as sand, bricks, soil, metals, roots, stems and leaves of raw materials, buds, disease spots, deteriorated grains and poisonous and harmful fungi. National food safety standard Edible vegetable oils (GB 19641-2015) stipulates the sensory requirements of oils and the limits of toxic and harmful fungi and plant seeds, as shown in Table 1 and table 2 respectively. The degree of impurity cleaning will directly affect the product quality, such as product purity, color, smell, processing technology and oil yield.
(2) The influence of oil refining process. Oil refining is to process a certain quality of oil to be refined into finished oil that meets the quality requirements of the national standard. The oil refining process has a direct impact on the quality indicators of the oil, such as transparency, color, taste, moisture and volatiles, impurities, heating test, acid value, soap content, peroxide value, freezing test, smoke point, etc. Oil quality indicators should be considered comprehensively. Each indicator is not completely independent. Many indicators are interrelated. For example, there is a direct relationship between soap content and taste, peroxide value, acid value and smoke point. The various processes of oil refining are also an integral whole that interacts and cooperates with each other. If a certain process has problems, other processes are also affected. Strengthening the operation of the subsequent process will make up for the shortcomings of the previous process to a certain extent. Therefore, the entire process of oil refining should be based on The factors that cause the unqualified oil to formulate the best processing technology plan. If the color of the finished oil does not meet the requirements, the reasons are as follows: there are more gums before decolorization, and the degumming effect in the degumming process is not good; improper temperature before decolorization produces pigment fixation; various influencing factors (temperature, Pressure, decolorization time, stirring, etc.) improper control; pigments are produced during the deodorization process. These factors should be combined to adjust the refining process plan to the best, such as modifying the pre-decolorization process to avoid pigment fixation, improving the decolorization process parameters to increase the decolorization effect, strengthening the degumming effect to reduce the gum content of the oil to be decolorized, and adjusting the deodorization parameters. (3) The impact of critical control points. The inaccurate determination of key control points and insufficient control points by enterprises will lead to "out-of-control" production and processing. For example, steaming and frying of raw materials in the production and processing of sesame oil by water-substitution method is not used as a key control point. Unstable temperature control causes the product's benzo\[a\]pyrene content to exceed the standard; the palm oil fractionation process is not used as a key control point, which will affect the solvent Many indicators such as residue exceeded the standard. (4) The influence of production instructions. Some process production operation instructions lack comprehensiveness because the process parameters are formulated without comprehensive consideration of processing principles and processing influencing factors, resulting in inaccurate or incorrect specific operation control. The operation instructions of each process should be continuously improved and perfected according to the principle of the process and the influencing factors, and its scientific nature should be improved to ensure the quality of oil. (5) Lack of quality control during the operation of the processing links, no production operation records, incomplete records, some rely on experience, only relying on experience such as touching, seeing, smelling, etc., so that it is difficult to trace the cause of quality problems, and there is no process improvement. Supported by scientific data, quality control is difficult to achieve.
1.3 Layout and facilities of processing workshops
In accordance with the requirements of "National Food Safety Standard Food Production General Hygiene Code" (GB 14881-2013): the design of plant and workshop should be rationally arranged according to the production process to prevent and reduce the risk of product contamination; plant and workshop should be based on the characteristics of the product , Production process, production characteristics and requirements for cleanliness during the production process. The operation area is reasonably divided, and effective separation or separation is adopted. It is usually divided into clean operation area, quasi-clean operation area and general operation area, or clean operation area and general operation area. The general work area should be separated from other work areas; work clothes should be worn when entering the production and processing work area, and special work clothes such as clothes, trousers, shoes, hats, etc. should be equipped according to the characteristics of the food and the requirements of the production process. The "National Food Safety Standard for Edible Vegetable Oils and Hygienic Specifications for the Production of Edible Vegetable Oils and Products" (GB 8955—2016) stipulates the filling area of edible vegetable oil: the filling area should be separated from other work areas to prevent cross-contamination; In the dressing room suitable for the number of people in the workshop, work clothes and personal clothing and other items should be placed separately; special work clothes should be worn when entering the filling workshop and other areas with high cleanliness requirements. In actual production, some enterprises have unreasonable process layout, cross flow of people and logistics, and high risk of product contamination; the filling area with higher cleanliness requirements is not separated from the general operation area, and the filling is not closed. The filling workshop lacks locker rooms, toilets and facilities, and work clothes are not dedicated to the filling workshop, which can easily cause cross-contamination of products. In terms of equipment and facilities, some companies have outdated equipment, insufficient equipment accuracy, and difficult to control parameters. Some equipment and facilities components and pipelines also use toxic and harmful components and plastic-related products, which affect the quality of grease or make grease plasticizers exceed the standard. Such as: gasket oil-resistant rubber sheet, made of nitrile rubber, which is a copolymer of 1,3-butadiene and acrylonitrile, and is mainly used for the sealing surface of sight glasses under low temperature and low pressure conditions; PTFE Vinyl padding, a small amount of hydrofluoric acid is produced after the decomposition of PTFE; some oil pipelines contain plasticizers, there are more than 100 types of plasticizers, and phthalate compounds are widely used, the softer the plastic The higher the product contains plasticizer.
1.4 enterprise management
The main problems of enterprise management are: (1) the quality system construction is not perfect, and the relevant enterprises have not formulated a perfect quality management system in accordance with the provisions of the food safety law. (2) The implementation of the system is not strict. In the actual production process, the implementation of the relevant enterprise system is insufficient, and the enterprise has not set up a management department or equipped with professional management personnel. The assessment mechanism is not perfect, and the system of some enterprises is still on paper, which is only used to deal with the assessment and acceptance of relevant departments, which is in vain and lack of practical operation guidance. (3) Lack of the concept of modern management, do not make full use of information management tools and ideas to effectively apply it to enterprise management. It is mainly reflected in the lack of production process management, lax quality control, incomplete records, quality problems can not be traced, resulting in no guarantee of product quality.
2 Measures to improve the quality of edible vegetable oil
2.1 Strictly control the quality of raw materials
Food raw materials must be qualified in batches when entering the factory. Check the quality certificate of incoming raw materials, and ensure that the batches inspected in the quality certificate documents correspond to the actual purchased batches; if there is no certificate of conformity, they must carry out self-inspection or entrust a qualified inspection agency to inspect and test items. It should be the factory inspection items specified in the raw material standards; the labeling and marking of the raw materials meet the requirements, and the raw materials entering the factory must record various information and quality conditions of the purchase channels to ensure that the quality of the raw materials of each batch and specification can be traced. The storage conditions of the raw materials meet the specified requirements, classified and tiered, and separated and stored separately; the storage temperature, ventilation, and insect (rat) prevention measures meet the standards; the storage of raw materials should be stored in accordance with the principle of first-in, first-out to avoid excessive storage of raw materials; raw material storage During the period of regular inspections and records, to prevent mildew, germination, insect infestation and pollution, improve the company's own quality inspection system, inspection equipment, the professional level of the inspectors meet the needs of food safety.
2.2 Strengthen the control of the production and processing process
Strengthening the control of the production and processing process is the key to ensuring product quality. The following points should be done: (1) Strengthen the pretreatment of oil. The cleaning process should be based on the characteristics of the oil, select the appropriate winnowing and screening, according to the density difference of the oil and impurities, select the winnowing equipment and wind speed, and select the screening equipment and method according to the difference in the size of the oil and impurities. It is necessary to improve equipment and facilities for peeling, crushing, rolling, steaming and frying, and formulate specific processing standards to ensure the quality of each link. (2) Strengthen the control of oil refining and scientifically formulate key control points for the refining of edible vegetable oils. The key control points of common edible vegetable oil: oil refining is deacidification and deodorization; sesame oil produced by water substitution method is the temperature of frying seeds and the oil is stirred; olive oil is selected as raw material and cold pressed at low temperature; palm (kernel) oil is the separation process. At the same time, enterprises must add more important control links in accordance with the characteristics of the products and equipment conditions to ensure the effective control of each process in the processing and production. The operating instructions for each process point, especially the key control point, must be scientifically formulated based on the control principle of its control point and the influencing factors of the control point. For example, in the process of alkali refining and deacidification of fats, free fatty acids, glycerides and alkalis in fats and oils undergo a series of chemical reactions, among which the main chemical reactions are neutralization, hydrolysis, saponification, etc. The main influencing factors are alkali and its dosage, alkali Liquid concentration, operating temperature, operating time, mixing and stirring, impurity content, and separation, washing and drying. The content of the work instruction must be comprehensive and without omissions, and the integrity of the process operation can be guaranteed to ensure the quality of the work. Specific production operators must have comprehensive professional knowledge, proficient operating skills, and a sense of responsibility; the key control point record data must be accurate and comprehensive, so that product quality can be traced, and it is convenient for continuous improvement and improvement of production technology.
2.3 Standardize the layout of processing workshops and equipment facilities
The edible vegetable oil processing enterprises should rationally arrange the production and processing workshops according to the varieties and characteristics of the edible vegetable oils, with smooth processes, separate flow of people and logistics; independent filling workshops, closed filling, complete hand washing facilities in the dressing room, and special work clothes. , Work clothes and other clothing and articles are stored separately to avoid cross-contamination; equipment and facilities are regularly maintained and updated in a timely manner to ensure stable operation of equipment and facilities and reliable and accurate parameters; materials used in processing workshops must not release harmful substances to avoid contamination of products; processing equipment and The related materials of the pipeline should not chemically react with the edible vegetable oil, and the related materials in contact with the edible vegetable oil should be food grade to avoid contamination of the product.
2.4 Strengthen corporate management and establish quality and safety awareness
Only by strengthening corporate management can the level of food quality and safety be improved. It is necessary to establish the concept that safe food is both "produced" and "managed". (1) The enterprise shall formulate a sound quality management system based on the Food Safety Law and relevant laws and regulations in combination with the actual situation of the enterprise, establish a scientific quality management system and mechanism, and cover the entire process from raw materials, processing, and finished products to the factory. The implementation of the quality management system must be in place, and the standardization and quality of work must be guaranteed by management. (2) It is necessary to combine modern management models and innovate management systems to meet the management needs of the market economy. (3) Implement the main responsibilities of enterprises and departments, and stimulate the enthusiasm and initiative of management staff and employees. (4) Strengthen modern science and technology management, make full use of the role of computers in oil processing, improve the technical level of equipment in oil processing enterprises, form an automatic control system with industrial computers as the core, integrate and optimize information resources in the platform, which is convenient for departments Close cooperation and communication between quality information will expand and enhance the effective management role.
2.5 strengthen personnel training and improve staff quality
The overall quality of high-quality personnel is the key factor to improve the quality level of edible vegetable oil. (1) Training of laws, regulations and standards. It mainly includes food safety law, national food safety standard, general hygienic standard for food production (GB 14881-2013), national food safety standard, hygienic standard for the production of edible vegetable oil and its products (GB 8955-2016), national food safety standard, standard for the use of food additives (GB 8955-2016) 2760-2014), detailed rules for examination of edible vegetable oil production license, product standards of edible vegetable oil, and relevant knowledge of food safety of national administrative departments. It cannot only improve the quality and safety awareness of employees, but also improve the standard production level of enterprises. (2) Production professional knowledge and technology training. It mainly includes raw material purchase, storage, control operation of key control point parameters, finished product storage, finished product delivery inspection training, etc. The training of each link should explain its principle, influencing factors and specific control operation methods. (3) Training of employees' sense of responsibility. Employees are an integral part of the enterprise. Employees should have the concept of taking the enterprise as their home, be dutiful in their posts, be loyal to the enterprise, consciously maintain the image and interests of the enterprise, abide by various systems of the enterprise, and actively ensure the food quality and safety level. Regular training should be given to the employees. The combination of internal training and external training cannot only improve the existing technical level of the enterprise, but also enable the employees to learn new knowledge and master new technology, so as to continuously improve the overall quality and level of the employees.
3 conclusion
To improve the quality of edible vegetable oil, it is necessary to have the source of quality and safety, the scientific production level, the sound quality management system and the improvement of the overall quality of staff. Raw material qualification is the premise to ensure product quality, strict control of the process is the key to ensure quality, a sound quality management system and staff safety awareness and quality improvement is the guarantee of quality and safety.
