A RESEARCH NOTE: ANTIOXIDANT EFFECTS ON COLOR OF AN IRRADIATED BOVINE MYOGLOBIN MODEL SYSTEM

To determine whether antioxidants could protect meat color during irradiation, we extracted myoglobin (Mb) from beef hearts, treated it with one of four antioxidants (control, citric acid [CA], ascorbic acid [AA], ethylenediamine tetraacetic acid [EDTA] or propyl gallate [PG]) and irradiated it at 0.00, 1.25, or 2.50 kGy. The myoglobin model system was then evaluated for pH; Commission Internationale de L'Eclairage (CIE) L *, a * and b * values; hue angle; chroma; and thiobarbituric acid reactive substances (TBARS). Adding CA and AA to the beef myoglobin model system resulted in higher L *, a * and b * values than did EDTA and PG, indicating that these samples were lighter, redder and more yellow. EDTA- and PG-containing samples were more similar to controls containing no antioxidants. Hue angle and chroma supported these findings. Irradiation had no effect on pH, color or TBARS. These results indicate that antioxidants have more influence on beef color than irradiation and that the acidic antioxidants have the potential for preserving color.

PRACTICAL APPLICATIONS

Irradiation has the potential to reduce the microbial load on meat products, producing safer foods for consumers. However, a number of reports have indicated that irradiation can compromise the bright, cherry red color of fresh meat. Off-color will result in consumer rejection of products that may be safe. Antioxidants have the potential to preserve meat color by affecting the state of myoglobin; however, studying these effects in vivo is challenging because of the complexity of the system. In this model system, which was devoid of enzymatic reducing systems and equivalents, the acidic antioxidants, ascorbic acid (AA) and citric acid (CA), were most effective in preserving the color of the pigment. These antioxidants appear to have the greatest potential for preserving fresh meat color during irradiation.     

SPECIAL DISTRICTS: A COMMON SOLUTION TO POLITICAL PRESSURES STEMMING FROM CITy-COUNTy FISCAL INEQUALITIES

Fiscal inequalities between cities and counties have long strained intergovernmental relations between these general purpose local governments. Historically they have tended to be competitive in their search for revenues but this competitiveness changed to greater cooperation as a consequence of the taxpayer revolts of the 1970s. Both cities and counties favored creation of special districts (with taxing power) to relieve some of the pressure on their own property tax structures. Traditional theories of government fragmentation have maintained that creation of special district governments further widens city-county fiscal inequalities; however, newer theories suggest the opposite. Through an analysis of increases in special districts and changes in city-county property tax level differentials, this study shows that creation of special taxing districts in the 1970s reduced property tax level differentials between cities and counties—an important economic and political effect in an age of taxpayer revolts aimed at city, county, and state property taxes but never at special district taxes.     

MEDIUM CHAIN TRIGLYCERIDE EFFECTS ON SENSORY AND PHYSICAL CHARACTERISTICS OF SHORTENED CAKES

Medium chain triglyceride (MCT) oil and corn oil were substituted for shortening (33, 50, 67 or 100%) in shortened cakes. Both MCT and corn oil affected batter specific gravity and fluidity (linespread). Baked cake volume decreased slightly at 33, 50 and 67% shortening replacement with both MCT and corn oil, but greatly at the 100% substitution level. Cake peak height decreased with corn oil but not with MCT oil substitution; air cell number decreased when oil was substituted 50%. Both oils decreased sensory graininess and surface oiliness/wetness; sensory lightness decreased at higher substitution levels. MCT or corn oil substitution had no effect on batter or cake color (L*, a* or b* values), oily flavor or sensory cohesiveness.     

Ultrastructure of Pork Liver after Freeze-Thaw Cycling and Refrigerated Storage

Pork liver was subjected to repeated freezing (-20°C) and thawing (+ 5°C) to simulate conditions of temperature abuse of frozen liver during commercial transport. Ultrastructure was compared to that of refrigerated pork liver. Liver cells deteriorated more with freezing and thawing (F-T) than with refrigerated storage (R-S). After one cycle F-T, hepatocyte organelles were damaged and cytoplasmic components appeared in the sinusoids. After four cycles F-T, membranes were extensively damaged and sinusoids contained organelles. The tissue organization was stable during six days of refrigerated storage, although cell structure deteriorated. Evidence from ultrastructure indicated that drip from F-T liver and R-S liver arose from different kinds of tissue damage.     

Butteroil Emulsification with Milk-Derived Membrane and Protein Fractions

Butteroil was emulsified by homogenization or ultrasound dispersal into aqueous phases containing milk lipid globule membrane, or combinations of membrane with lipid globule-derived and milk serum proteins. Stable emulsions containing about 50 mg protein/g butteroil were produced with all combinations. Protein composition of emulsions closely reflected protein composition of starting materials. Emulsions of equal stability, and with churn times equivalent to that of cream, were obtained with unprocessed butteroil and with a cholesterol-reduced butteroil produced by steam-stripping. Electron microscopic examination of fixed material showed that emulsions produced with all formulations predominantly were of the water-in-oil type, and not the oil-in-water type typical of milk lipid globules.