F. J. Francis

Roselle (Hibiscus sabdariffa L.) anthocyanins as colorants for beverages and gelatin desserts

A dry powdered pigment extract was prepared from a Roselle liquid concentrate obtained from Trinidad. The pigment base was added to two dry pack foods, a beverage mix and a gelatin dessert, and evaluated under various temperature and humidity conditions. During a 16-week storage period, color, flavor, and pigment stability were evaluated versus those of Red No. 2. All samples were less stable than those with Red No. 2 but showed good stability up to 4 weeks of storage, after which, the rate of pigment degradation accelerated. Reconstituted products showed good light and refrigeration stability but the roselle powder imparted an unacceptable flavor to the products.

Changes in Chromatographic Profile of Anthocyanins of Red Onion During Extraction

The role of acidifying agent in extracting anthocyanins from red onions was investigated. Cl- of HCl disrupted complex structures present in onion tissue to release anthocyanins and also induced formation of other complexes containing the pigment. Formate did not produce these effects. A schematic was developed to illustrate the interaction and decomposition of anthocyanin fractions during HCl extraction. The implications of the presence of Cl- in the extractant on interpretation of extraction results were discussed. Anthocyanins possibly acylated with non-cinnamic acids were considered to be particularly affected by mineral acids in the extractant.

Stability and Complexation of Cyanidin-3-Giucoside and Raspberry Juice Extract in the Presence of Selected Cations

The stability and color of purified cyanidin-3-glucoside and raspberry juice extract in the presence of selected metal ions was investigated. Production of metal-anthocyanin complexes was suggested by changes in color of the samples as shown by L, a, and hue angle values. Complex formation was indicated by HPLC in raspberry juice samples treated with Sn++ but not in samples of purified cyanidin-3-glucoside. According to the colorimetric values, complex formation occurs with cyanidin-3-glucoside and A1+++ at pH 2.0 and 3.0 and with Sn++ at pH 4.0 and 3.0. Similar complex formation occurs with these metals and raspberry juice extract at the same respective pH values.

Effect of Anthocyanin Preparations as Colorants on Hygroscopicity of Dry-Pack Foods

The equilibrium relative humidity isotherm of a cherry beverage base and a strawberry gelatin dessert mix colored with anthocyanins from grape skins, cranberries and roselle was evaluated versus a Red No. 2 control. As well, the water vapor transmission rate of the packaging material was evaluated to evaluate probable shelf-life. Results indicated that physical parameters, such as hygroscopicity, must be considered in estimating effects of the use of natural colorants in foods as well as the color and chemical stability normally investigated.

Food vs. Fuel

The long lines of motorists waiting for gasoline in the 1970s sent shock waves through the American public. In the United States big cars were part of the national way of life. We were used to driving wherever and whenever we wanted. Gasoline was cheap. The rest of the world taxed gasoline very heavily, thereby encouraging the development of small fuel-efficient cars. In the early 1970s, a group of countries formed a cartel called the “Organization of Petroleum Exporting Countries” (OPEC), and raised the price of crude oil by a factor of 10–15. The search for alternative fuels began in earnest. One of the solutions was “gasohol,” a blend of 10% ethyl alcohol (ethanol) and 90% gasoline. The ethanol could be produced from the large surpluses of corn available in the United States. In 1980, Congress passed legislation calling for production of 500 million gallons of ethanol for fuel in 1981, one billion gallons in 1982, rising to 10 billion gallons in 1990. The 1990 goal would have required about 100 million tons of corn, which is slightly less than half of the 1982 corn crop (210 million tons). This did not happen and, and we may be thankful that it didn’t, since it would have raised the cost of food.

Effect of Cinnamic Acid on Anthocyanin Stability in Cranberry Juice

The direct effect of cinnamic acid on anthocyanin stability in cranberry juice without added ascorbic acid was investigated. The concentration of cinnamic acid was determined throughout the storage study by high-performance liquid chromatography (HPLC), and results indicate no loss of cinnamic acid either due to pasteurization or storage. Cinnamic acid was found to have no significant effect on anthocyanin stability in cranberry juice during storage at ambient temperature at the levels used in this study.

Application of Color Theory to Commodity Areas

The measurement of color in food products has been applied in commodity areas where there is an economic need. This will be illustrated by several examples.

EFFECT OF MAGNESIUM CARBONATE AND SODIUM PHOSPHATE ON THE EXTRACTION OF CHLOROPHYLL-LIKE PIGMENTS AFTER THERMAL PROCESSING OF SPINACH PUREE

Because buffers are important in maintaining green color in vegetable purees, a study was undertaken to determine if sodium phosphate and/or magnesium carbonate would effect extraction of some or all of the chlorophyll-like pigments in spinach puree and thus interfere with their analysis. Samples were prepared with and without addition of the above additives and pigment analyses were carried out for chlorophylls, chlorophyllides, pheophytins, and pheophorbides. It was found that addition of sodium phosphate and/or magnesium carbonate prior to blanching and processing caused chlorophyll b, pheophytin a, pheophorbide a, and pheophorbide b to be bound to some extent. Pheophytin b was unaffected Chlorophyll a, chlorophyllide a, and chlorophyllide b were present in such small quantities that no conclusions could be drawn about their extractability. This phenomenon is an important consideration in the analysis of chlorophyll-like pigments in buffered systems and also might supply a suitable means for removal of...

Potential Sources of Protein

The world’s population currently derives about 70% of its protein from plant sources. It is unlikely that the proportion of protein from animal sources will increase in the foreseeable future, in view of the increased pressure on the land for total food production.

Nutrition for Athletes

The nutritional requirements of most athletes are satisfied, in general, by the same set of guidelines discussed previously, which include meeting the RDAs or the recommended safe levels for all nutrients. The fact that we have included a separate chapter on athletic nutrition should not imply that there are unique dietary patterns for the health of the athlete. This is not the case, and a healthy person with a good diet will become a healthy athlete with a good diet. However, because so many people are involved in athletics in one way or another, it was decided to include some specific information. From 1970 to the present, participation in amateur softball has increased from 16 to 30 million, golf (15 rounds or more) from 9,700,000 to 13,650,000, and tennis from 10,655,00 to 25, 450,00 (Grandjean, 1982) to say nothing of all the other sports.