This chapter discusses margarine as well as vegetable oil margarine and butter substitutes containing less than 80% fat. These products are referred to as table spreads. The table spread category has undergone great changes in recent years and continues to change rapidly. The market for table spreads, which was originally driven by cost, has now been impacted mainly by health concerns. Claims relative to the cholesterol content, polyunsaturated fats, saturated fats, total fat, and trans-fat content have become important issues.



Historical production of spreads and their relationship to butter are discussed. Legal requirements for the composition and labeling of margarine and table spreads are given. Such information is necessary for formulating products to meet specific demands. Labeling is regulated and set forth in the Code of Federal Regulations. Labels concerning health and nutrient content are detailed. Product characteristics of importance are spreadability, oil separation, and melting. The various oils sources in vegetable oil margarines and spreads are discussed in terms of their properties, blending, and specifications.



There is a wide range of formulations used in the margarine industry. However, there are five basic processing operations: emulsification, cooling, working, resting, and packaging. Attention is given to the factors impacting on the deterioration and shelf life of the products.


Keywords:

margarine;
spreads;
butter;
labels;
nutrition;
health claims;
spreadability;
source oils;
blending;
specifications;
formulations;
flavor;
vitamins;
processing;
low-calorie spreads;
deterioration;
shelf life

Margarines and Spreads

Catalytic hydrogenation of vegetable oils, viz. soybean oil, is an established technology in food industry. Its major concern is the hydrogenation of autoxidation-sensitive polyunsaturated fatty acid tails to stabilize the vegetable oil. Flash-hydrogenated oils find application in cold dressings and cooking oils. Somewhat deeper partial hydrogenation converts the vegetable oils into (semi-) solid fat products with different organoleptic and melting characteristics for use in various food applications, such as margarines and shortenings. The catalytic hydrogenation of vegetable oils has a history of more than 100 years with fluctuating popularity, depending not only on economical factors but also on nutritional findings. For more than a decade, the use of industrially hydrogenated fats in food products was controversial because of the presence of trans fatty acid isomers. The presence of geometrical isomers is an inherent consequence of the Horiuti-Polanyi hydrogenation mechanism, which describes the stepwise and reversible addition of adsorbed hydrogen atoms to the adsorbed double bond on the catalyst surface. After reaction with one adsorbed hydrogen atom, a halfhydrogenated intermediate is formed, which is either reduced by the reaction with a second hydrogen atom, leading to the formation of a saturated bond, or it loses a hydrogen atom prior to desorption, potentially leading to the formation of geometric (trans) and positional isomers of the starting unsaturated fatty acid. Although triglycerides that contain trans fatty acids have ideal melting characteristics, they are associated with a negative health impact, thus imposing the replacement of catalytic hydrogenation by other technologies, such as fractionation and catalytic interesterification, which yield “zero trans” fatty products. The hydrogenation technology experiences industrial interest, because it allows the modification of fatty acid and triglyceride compositions in a single step. As hydrogenation is a catalytic process, novel catalyst design is key to the production of (semi-solid) fats with acceptable organoleptic, melting, and nutritional properties, provided the “trans issue” can be circumvented. Other fat/oil applications, such as the production of essentially trans-free biolubricants and many renewable chemicals, could also benefit from new advances of catalytic vegetable oil hydrogenation. The present essay reviews briefly the history of the catalytic hydrogenation of vegetable (edible) oils and illustrates how trends in food chemistry research converge with new nutritional insights. Certain novel promising catalytic developments, which were recently reported in this journal, are highlighted, such as the trans-free chemocatalytic hydrogenation, which shows unprecedented types of shape selectivity, and trans-selective enzymatic hydrolysis. This pioneering work uses new concepts, which could pave the way to alternatives to the nowadays prominently present palm-based shortenings. It illustrates that, 100 years after the first industrial production of hydrogenated fats for food products, selective hydrogenation of vegetable oils is still an exciting research domain of utmost importance for the food industry and beyond (Scheme 1).

Is there still a Future for Hydrogenated Vegetable Oils

Rules of formulation are discussed. Some characteristic properties of raw materials and finished products can be instrumentally determined, others more empirically. Such approach applies to raw material interchangeability as well. Formulation problems will differ according to the type of finished product: margarines, shortenings, salad dressings, deep frying fats, specialty fats. They will also vary depending on the user: household, catering, manufacturer or food industry. Modern methods for formulation are then described.

Finished product formulation

Publisher Summary Production of suitable frying fats and oils starts with crude fats or oils extracted from oil seeds, tree fruits and nuts, and animal or marine fatty tissues. This chapter discusses the successive steps of extraction, refining, and formulation of fats and oils into frying media. It provides a brief overview of the processing of fats and oils. There are many steps from raw material to finished product and each must be done correctly to ensure maximum quality in a frying fat. The final user is often far removed from both the processing and the processor. Because of this, reliance must be placed on either their own purchasing specifications or manufacturers' specifications. Unfortunately, adherence to agreed-on specifications does not always mean that the product was processed in an optimal manner. The assurance of expected quality most often is a result of experience with suppliers, working closely with suppliers, an actual performance test, or a combination of the three.

Production and Composition of Frying Fats

Fats and Oils Formulation

High quality shortenings and margarines may be produced using soybean oil as the only fat source or using soybean oil as the primary fat source with the addition of a small amount of hydrogenated cottonseed or palm oil to provide crystal stability. These shortenings and margarines are manufactured by direct hydrogenation or by blending hydrogenated and/or unhydrogenated base stocks. The properties of soybean oil preclude the need for processes other than hydrogenation and blending to produce most margarine and shortening products. It is possible to design an integrated base stock program in which a limited number of base stocks may be used jointly in margarine and shortening formulations. This type of base stock program results in fewer hydrogenation department heels and simplifies scheduling of the hydrogenation department as well as scheduling of overall operations. Solid fat index (SFI) is the analysis used for final product consistency control. While base stocks are blended to meet a final SFI requirement, this analysis is too time-consuming to be used in hydrogenation control and individual hydrogenation batches are controlled using refractometer number and congeal points. Finished product characteristics are a result of decisions that must be made regarding characteristics such as plastic range and AOM stability, which are incompatible.

E. G. Latondress

Papers

Formulation of products from soybean oil