Classifications

• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11B—PRODUCING, e.g. BY PRESSING RAW MATERIALS OR BY EXTRACTION FROM WASTE MATERIALS, REFINING OR PRESERVING FATS, FATTY SUBSTANCES, e.g. LANOLIN, FATTY OILS OR WAXES; ESSENTIAL OILS; PERFUMES
  • C11B3/00—Refining fats or fatty oils
  • C11B3/12—Refining fats or fatty oils by distillation
  • C11B3/14—Refining fats or fatty oils by distillation with the use of indifferent gases or vapours, e.g. steam
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11B—PRODUCING, e.g. BY PRESSING RAW MATERIALS OR BY EXTRACTION FROM WASTE MATERIALS, REFINING OR PRESERVING FATS, FATTY SUBSTANCES, e.g. LANOLIN, FATTY OILS OR WAXES; ESSENTIAL OILS; PERFUMES
  • C11B3/00—Refining fats or fatty oils
  • C11B3/001—Refining fats or fatty oils by a combination of two or more of the means hereafter

Definitions

• the present invention is concerned with a method for refining edible oils with the aim to avoid any refining step which is not considered natural.
• the purification process of a crude edible oil usually comprises the removal of phospholipids (degumming) by means of water, acid and/or a sorbent.
• Oils for which degumming was the first refining step still contain substances which have a negative influence on taste, smell and keepability. Those substances comprise inter alia free fatty acids and destabilising peroxydes.
• deodorisation For the removal of several unwanted substances a process is used called deodorisation, which can be performed by stripping the oil with a stripping medium e.g. steam, at temperatures above 200°C. Stripping at such relatively high temperatures has the disadvantages that the oil may decompose and that unwanted and sometimes even toxic compounds are formed.
• oils having a flavour which is much alike the natural flavour might be much appreciated by oil consumers.
• the natural flavour of an oil may suffer from the presence of substances which contribute to an off-flavour perception.
• the problem is to remove the flavour deteriorating substances while preserving and preferably increasing the flavour improving substances, without being hindered by the disadvantages of the processes according to the state of the art.
• the object of the invention is to provide a mild and cheap refining method for the purification of edible oils and in the same time to provide oils with a specific flavour profile or even without any flavour (bland flavour).
• a method for refining a triglyceride oil which comprises acidifying the oil and removing substances which separate from the oil, followed by gas stripping of the oil at a temperature of 60-160°C, characterised in that the stripping treatment is preceded by a heat treatment, which consists of keeping the oil at a temperature of 30-180°C.
• the flavour profile of the oil can be modified, including the complete removal of flavour.
• the treatment of the invention is denoted as mild in contrast to the usual, demanding refining treatments comprising use of chemicals and/or high temperatures, such as alkaline deacidification, bleaching and deodorising at temperatures >200°C.
• the temperature of the heat treatment preceding the stripping of the oil is in the range of 30-180°C, preferably 40-160°C and more preferably 60-160°C.
• a suitable duration of the heat treatment may be in the range of one hour to one week, and preferably is between 5-40 h.
• an adsorbent for example silica
• silica may be admixed before filtration.
• the duration of the treatment may be considerably shortened.
• an additive consisting of a relatively small amount of an acid and/or an antioxidant, preferably a tocopherol
• the duration of the treatment may be considerably shortened.
• a suitable time is 14-15 h at a temperature of about 120°C, but with the additive the same effect is obtained within 7-8 h at the same temperature.
• the amount of additive is 10-2000 ppm, preferably 100-2000 ppm calculated on oil.
• a suitable amount is 500 ppm.
• the acid may be dissolved or dispersed in a suitable harmless liquid.
• natural acids are used, which may advantageously be selected from the group comprising citric acid, tartaric acid, malic acid, lactic acid and acetic acid.
• Such natural acids are preferred as they contribute to the 'green' character of the refining method of the present invention.
• natural extracts or compositions containing such acids are mentioned, like lemon-juice and the like.
• the gas stripping is carried out according to methods known in the art with the proviso that preferably temperatures are practised which are moderate. Moderate stripping temperatures suitable for the purpose of this invention are defined as being in the range of 30-200°C. The temperature according to the invention is 60-160°C. A suitable period of time for gas stripping is 1-100 h, preferably 1-10 h. By properly attuning stripping time and temperature it is possible to obtain an oil with a characteristic and attractive flavour profile or even an oil being completely disposed of flavour (bland flavour).
• the process according to the invention can be used with any kind of edible oil, either from animal or vegetable origin, it is particularly suitable for the purification of natural oils which have been obtained from a natural source and which after a mild refining treatment are ready for direct consumption such as sunflower oil, palm oil, olive oil, rape seed oil etc.
• the present refining treatment may be combined with other known mild treatments such as washing with water, centrifuging or filtration, comprising membrane filtration.
• Stripping is suitably effected by blowing steam or an inert gas such as nitrogen through the oil.
• Bland flavour oils which have been obtained by the process of the invention are characterised by a free fatty acids content of at least 0.1 wt.% and a POV-value of less than 1 or even less than 0.5.
• the invention it is possible to improve and to attune or to remove the flavour of an edible oil applying mild processing conditions and without the addition of non-natural flavour imparting substances to the oil.
• the oil may be featured as a "natural” oil for still another reason because the process can dispose of the usual bleaching treatment which removes carotenoids, so that the natural colour of the oil is retained.
• the oils according to the invention can be used as such for consumption, or they may be processed further.
• the invention therefore finally provides an edible composition containing a refined oil according to the invention.
• the refined oils according to the invention may be used for example as ingredients in the preparation of edible compositions, such as water and oil emulsions, e.g. mayonnaise, dressings, fat spreads or processed cheese. Since the fat component of such products may be quite substantial, consequentially the flavour of the oil may contribute considerably to the flavour of the end product.
• the oil refined according to the invention still has most of the original carotenoids present, whereas an oil refined according to the art has no carotenoids left.
• the oil refined according to the invention can therefore be used as a natural colourant in products, e.g. spreads, having the advantage that no taste is present which could interfere with the desired taste of the product.
• a reference sample (A) comprising the same oil, was subjected to the same degumming pretreatment, however, after filtration it was deodorised immediately by stripping with steam at 180°C for 5 h.
• Another reference sample (B) comprising the same oil, was treated like sample (A) but stripped at 120°C for 5 h.
• Table III the analytical data of the crude oil, the oil refined according to the invention and reference sample (A) are listed. After deodorization the fresh taste of the oil treated according to the invention and the reference sample A was excellent. After 6 months of storage at 15°C in plastic bottles the taste of both treated oils was still qualified as excellent.
• Table III FFA P Fe E 232 E 268 POV Crude 0.69 13 0.14 2.39 0.24 4 Invention 0.65 ⁇ 1 ⁇ 0.01 2.54 0.61 0 Ref. A 0.03 ⁇ 1 ⁇ 0.01 n.m. n.m. 0

Landscapes

• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Microbiology (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Edible Oils And Fats (AREA)
• Fats And Perfumes (AREA)

Priority Applications (2)

Applications Claiming Priority (4)

Publications (2)

Family

ID=8211097

Family Applications (1)

Country Status (11)

Cited By (3)

Families Citing this family (18)

Family Cites Families (7)

• 1993
  • 1993-11-16 DE DE69310543T patent/DE69310543T2/de not_active Expired - Fee Related
  • 1993-11-16 ES ES94901805T patent/ES2102806T3/es not_active Expired - Lifetime
  • 1993-11-16 WO PCT/EP1993/003213 patent/WO1994012596A1/en active IP Right Grant
  • 1993-11-16 AU AU56246/94A patent/AU672858B2/en not_active Ceased
  • 1993-11-16 EP EP94901805A patent/EP0672096B1/en not_active Expired - Lifetime
  • 1993-11-16 DK DK94901805.5T patent/DK0672096T3/da active
  • 1993-11-16 CA CA002150949A patent/CA2150949C/en not_active Expired - Fee Related
  • 1993-11-16 AT AT94901805T patent/ATE152761T1/de not_active IP Right Cessation
  • 1993-11-23 ZA ZA938754A patent/ZA938754B/xx unknown
  • 1993-11-30 TR TR01088/93A patent/TR28200A/xx unknown
  • 1993-12-01 MY MYPI93002547A patent/MY131379A/en unknown

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