Edible Fat and Oil Processing

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Introduction

There are a number of suppliers of oil and fat products used for edible purposes. These products include, but are not limited to olive oil, peanut oil, soybean oil, sunflower oil, lard, shortening, butter, and margarine. The raw materials for these products include animal by-products, fleshy fruits (palm and olive), and oilseeds. The crude fats and oils from these sources are recovered using a number of methods such as rendering, pressing and extracting with solvents. Some oils, such as virgin olive oil, are ready for consumption after this initial step (pressing), while other requires additional processing. The extent of fat and oil processing depends on the source, quality, and nature of the end use.

Alkali Refining

The growing demand, in the United States especially, for bland-tasting, stable oils and shortenings for the end user has driven the development of extensive processing techniques. The constituents of crude fats and oils that contribute to unwanted flavor and color are free fatty acids, waxes, color pigments, phospholipids (gums), oxidized products, metal ions, and carotenoids. Many of these undesirables can be removed by Alkali refining. Alkali refining is the removal of these unwanted items by a chemical reaction with an alkali (caustic soda). This process is completed by a four step process: Conditioning, Neutralization, Washing, and Drying. The fats are heated between 40o and 85oC and treated with an aqueous solution of sodium hydroxide or sodium carbonate. Conditioning transforms non-hydrate phospholipids into their hydrate form by breaking down metal/phosphatide complexes with a strong acid. In neutralization the removal of free fatty acids and residual gums takes place. Washing is the removal of residual gums by hot water. And drying is the removal of moisture under a vacuum.

Inductive Conductivity can be used to provide a continuous, on-line indication of the aqueous Alkali solution concentration. The aqueous emulsion formed by the impurities is drawn off the bottom of the tank (in batch refining) or centrifuged off (in continuous refining). After alkali refining, the oil is usually washed with water to remove any residual alkali or emulsion. Measuring the conductivity of this wash water can indicate its quality. Clean water with low dissolved solids will exhibit low conductivity.

Inductive Conductivity

Water Refining

Also known as degumming, water refining consists of treating the crude oil with a small amount of water. "Degumming" is where phosphotites in the Oil are hydrated with water and then removed by separating in the Centrifugal Separators. The Degummed Oil is then subject to neutralization with caustic soda where the free fatty acids are converted into residual gums and are separated in hermetic separators. The neutralized oil is then washed and dried.

The "gummy" emulsion of phospholipids created by the treatment with water is then centrifuged off. In the case of corn and soybean oil, this emulsion can be dried to produce a substance known as lecithin, which is used as a emulsifier in many applications. Because of this, the water used in the degumming process needs to be of high quality. Any impurities in the water will end up in the product after the drying process. Once again, conductivity can provide a low maintenance indication of water quality.

Deodorization

Most fats, even after refining, have characteristic flavors and odors, and vegetable fats especially have a relatively strong taste that is foreign to that of butter and are considered undesirable. In order to produce a tasteless, butter-like fat, these oils may undergo deodorization. To do so steam is blown through the heated oil to distill the volatile components responsible for these flavors and odors. Of course, in order to generate steam you will need water, clean water. pH and conductivity measurements of the feed water are mandatory in this process to ensure the protection of the process equipment from corrosion and scaling. Other than water, you need heat to generate the steam. Proper control of excess oxygen in flue gas allows the boiler to be operated efficiently and safely.

Hydrogenation

For many purposes, it is desirable for the oil to be solid, or semi-solid (margarine and shortenings). The process that converts liquid oils to higher-melting solids is called hydrogenation. The process consists of dispersing hydrogen atoms to double bonds of a molecule through heated oil in the presences of a catalyst¹. Cylinders from a vendor may supply the hydrogen, but some plants produce it on-site. This usually involves the electrolysis² of water to form oxygen and hydrogen. It is critical for the water used in the process to be pure. Contacting conductivity can be used to ensure the quality of the water in order to prevent damage to the expensive equipment used to generate the hydrogen. The purity of the hydrogen used in this process is critical, both for the product quality, and the process efficiency. Gas Density can be used to measure the purity of the hydrogen gas leaving the generation system.

Notes

  1. A catalyst is a substance which speeds up a reaction, but is chemically unchanged at the end of the reaction.
  2. Electrolysis is a method of separating chemically bonded elements and compounds by passing an electric current through them.

Summary

There are many points in the processing of edible fats and oils that benefit from the use of analytical measurements. Inductive Conductivity, Contacting Conductivity, Gas Density and pH can be utilized to increase the quality of the end product, as well as protecting expensive process

Product Recommendations

Yokogawa SC4A and the SC42 seriesYokogawa sensor

Sensors:

For measurements of low conductivity, contacting sensors are recommended such as the Yokogawa SC4A and the SC42 series. For cleaning and rinse processes, inductive conductivity offers the best solutions with a minimum of maintenance.

For pH measurements the FU24 All-in-One pH/ORP sensor is the best solution. By incorporating the successful Yokogawa patented Bellow system integrated in the FU24 electrode, the built-in bellows ensures immediate interior pressure equalization to the outside pressure, making the sensor virtually insensitive to external pressure variations and potential plugging.

EXAxt450

Holders:

All of Yokogawa sensors can be installed online, retractable, or flow-thru, depending on which installation the customer requirements. Material construction for Yokogawa sensors and holder may vary, but typically is 316SS.

Analyzers:

The Yokogawa model EXAxt450 analyzers should be used for applications where 115 VAC equipment is required, The Yokogawa Model FLXA21 analyzer should be used for application where 24 VDC loop powered equipment is required.

Related Products & Solutions

2-Wire Transmitter/Analyzer FLXA202/21

FLEXA ™ 시리즈 분석기는 산업용 설비의 연속 온라인 측정에 사용됩니다. 단일 또는 이중 센서 측정 옵션이 있어 가장 유연한 2 선식 분석기입니다.

4-Wire pH/ORP Analyzer PH450

PH450 pH와 ORP 분석계인 PH450은 pH와 온도, ORP(Redox) 측정을 결합한 다변형 분석계로, mA 전류 출력 2개, 독립적인 SPDT 접점 출력 및 HART 등 다양한 출력기능을 통해 활용할 수 있습니다. 

All-in-One Digital Smart pH/ORP Sensor FU20F

디지털 통신과 내장형 인텔리전스의 센서를 직접 결합하여 "Simple is best" 라는 모토를 유지하는 올인원 pH 및 ORP디지털 스마트 센서입니다.

All-in-One Digital SMART pH/ORP Sensor FU24F

FU24F는 까다로운 pH 어플리케이션을 위한 내화확성 PPS40GF 바디로 제조된 디지탈 스마트 pH/ORP 센서입니다.

All-in-One pH/ORP Sensor Series FU20/FU24/PH20

PH20, FU20, FU24는 올인원 타입의 pH 와 ORP 센서로서 Yokogawa가 "Simple is best" 이라는 모토를 센서 기술에 어떻게 적용하는 지를 보여줍니다.

Contacting Conductivity Sensors SC42/SC4A(J)

수용액서의 전도도 측정은 물에서 불순물을 측정하는데 점점 더 중요해지고 있습니다. Yokogawa는 극한 조건에서도 이러한 측정에 대응할 수 있는 정밀 센서와 계측기를 설계하고 있습니다.

GD40 Detector

GD40 디텍터는 본질 안전 및 방염, 방폭 어플리케이션을 위하여 설계되었습니다. 모든 허용된 응용 프로그램에 대하여 실질적으로 유지보수가 필요없습니다.

GD402 Analyzer

모델 GD402 가스 밀도 분석계 및 모델 GD40 디텍터는 가스 밀도의 연속 측정뿐만 아니라 비중 및 분자량을 포함한 몇 가지 중요한 파라미터를 제공합니다. 모델 GD402는 비방폭 및 방폭 어플리케이션에 대한 요구 사항을 충족하기 위하여 두 가지 버전으로 설계된 마이크로 프로세서 기반의 컨버터 입니다. 

Pure Water (Low) Conductivity sensors SC4A(J)/SC42

반도체, 전력, 물 및 제약 산업에서 발견되는 낮은 전도도 어플리케이션을 위해 만들어진 센서는 편리한 소형 스타일입니다.

Pure Water (low) Conductivity/Resitivity Analyzers

반도체, 전력, 수자원 및 제약 산업에서 발견되는 낮은 전도도 응용 분야를 대상으로합니다. 이 분석기는 전도도 센서에 접촉하여 작동합니다.

SENCOM PC Software

SENCOM PC 소프트웨어, SPS24는 향상된 신뢰성과 공정 안전을 위해 pH/ORP 센서의 성능을 최적화하는 고유한 수단을 제공합니다. 이 소프트웨어를 통해 운전자는 pH/ORP 센서 성능을 모니터링하고 다양한 파라미터를 조정 및 구성할할 수 있습니다.

 

Gas Density/Hydrogen Purity Analyzer

가스 밀도 검출기 및 분석기는 가스 밀도의 연속 측정을 제공합니다. 뿐만 아니라 비중 및 분자량을 포함한 여러 가지 중요한 파라미터를 제공합니다.

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pH and ORP Sensors

pH 전극 및 센서는 pH 측정의 감지 부분입니다. Retractable, flow-though, 침적 및 직접 삽입을 포함한 다양한 설치 옵션이 있습니다.

적절한 pH 전극 / 센서 선택은 최적의 측정 결과를 위해 중요합니다.

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