Z.J. Hawrysh

Oat bran concentrate bread products improve long-term control of diabetes : A pilot study

OBJECTIVE To evaluate the long-term effects oat bran concentrate bread products in the diet of free-living subjects with non-insulin-dependent diabetes (NIDDM) via dietary, clinical, and biochemical methods. DESIGN A 24-week crossover study consisting of two 12-week periods. SUBJECTS/SETTING Eight men with NIDDM (mean age = 45 years) who lived in the community. Glucose and insulin profiles were conducted in a clinical investigation unit. INTERVENTION Palatable, high-fiber, oat bran concentrate (soluble fiber [beta-glucan] content = 22.8%) bread products were developed. Four randomly chosen subjects ate oat bran concentrate breads first; the other subjects ate control white bread first. MAIN OUTCOME MEASURES Dietary intake (four 48-hour dietary recalls per period) was assessed. Blood glucose and insulin (8-hour profiles) and lipid parameters after fasting were measured (at 0, 12, and 24 weeks). STATISTICAL ANALYSES PERFORMED Analysis of variance and repeated-measures analysis of variance. RESULTS Total energy and macronutrient intakes were similar in both periods. Mean total dietary fiber intake was 19 g/day in the white bread period and 34 g/day (9 g soluble fiber per day from oat bran concentrate) in the oat bran concentrate period. Body weight remained stable. Mean glycemic and insulin response areas (area under the curve) were lower (P < or = .05 and not significant, respectively) for the oat bran concentrate period than the white bread period. After breakfast, area under the curve for the oat bran concentrate period was lower for glucose (P < or = .01) and insulin (P < or = .05); insulin peak was reached earlier (P < or = .05) than in the white bread period. Dietary fiber intake was correlated negatively with insulin area under the curve (P < or = .05). Mean total plasma cholesterol and low-density lipoprotein cholesterol levels were lower (P < or = .01) in the oat bran concentrate period than in the white bread period. In the oat bran concentrate period, the mean ratio of low-density lipoprotein cholesterol to high-density lipoprotein cholesterol was reduced by 24% (P < or = .05). CONCLUSIONS The well-accepted oat bran concentrate bread products improved glycemic, insulinemic, and lipidemic responses.

Endurance-exercised growing sheep: II. Tenderness increase and change in meat quality

A study was conducted to examine the effect, in ram lambs, of chronic treadmill exercise, on meat quality. A secondary objective was to relate changes in tenderness to metabolic and chemical phonomena. Meat quality traits, including instrumental measurements of tenderness and thaw and drip losses, were recorded for two muscles from the hind limb (semimembranosus SM; vastus lateralis, VL). Chemical analyses, including total and soluble collagen, total and myofibrillar protein, and myofibrillar fragmentation were also performed. Muscles from exercised sheep were significantly more tender than muscles from their control counterparts. A larger myofibrillar protein to total collagen ratio was observed in the VL muscles from exercised sheep (P < 0·01) which probably contributed to the observed increase in tenderness. However, similar results were not observed for the SM muscle. The tendency for a slightly higher pH at similar post-mortem temperatures in meat from exercised sheep may also have contributed to the increased tenderness.

Suprathreshold sour taste intensity and pleasantness perception with age

Magnitude estimates for perceived intensity and pleasantness of suprathreshold concentrations of citric acid in solution and drink were examined in 180 healthy, free-living subjects divided into three groups: young (20-29 years), old (70-79 years) and very old (80-99 years). Psychophysical functions showed significant age effects. For both aqueous and food systems, the old gave higher intensity estimates to high acid concentrations and lower intensity estimates to low acid levels compared to the young and very old whose estimates were comparable. Sex had a significant effect on the intensity estimates with the women giving low acid levels lower estimates and high acid levels higher estimates than the men. All subjects gave low acid levels in solution lower intensity estimates than comparable drinks while at high concentrations, higher intensity estimates were given to solutions than drinks. Trend analysis of pleasantness estimates indicated significant age group differences. For both systems, the breakpoint, the acid level assigned the highest pleasantness estimate was lower for the young than for the elderly.

Sensory and chemical stability of tortilla chips fried in canola oil, corn oil, and partially hydrogenated soybean oil

The effects of canola, corn, partially hydrogenated soy (PHS), partially hydrogenated canola (PHC), and low-linolenate canola (LLC) oils on sensory and chemical attributes of tortilla chips were determined initially, after Schaal storage for 8 and 16 d (S8 and S16), and after practical storage for 16 and 24 wk (P16 and P24). Fresh chips were similar to each other in characteristic and off-odors/flavors, except that PHC chips had the lowest characteristic and highest off-odor/flavor. All S8 chips had similar lower (P<0.001) characteristic and greater off-odor/flavor scores than hidden reference chips, but PHC chips had a more intense off-odor than did LLC chips. After S16, canola chips had the lowest (P<0.001) characteristic and highest off-odor/flavor; all other chips were similar. At P16, canola, PHC, and LLC chips had slightly higher (P<0.001) characteristic odor/flavor scores than other chips. After P16 and P24, all stored tortilla chips had lower characteristic odor/flavor scores than hidden reference chips. Rancid, painty, buttery odor/flavor, and bitter flavor notes were detected in Schaal and practically stored chips. Stored chips from all oils were similar in color and crispness. The peroxide value and thep-anisidine value for oils extracted from Schaal-stored chips tended to support panelist data; results from similar analyses of practically stored chips did not. Peroxide values andp-anisidine values for stored used frying oils and the corresponding sensory data for stored chips generally did not agree. Results indicate considerable potential for increasing use of canola oil products for frying tortilla chips.

The Influence of Cooking Temperature on the Eating Quality of Beef from Bulls and Steers Fed Three Levels of Dietary Roughage

Abstract The cooking losses and subsequent eating quality of semimembranosus (SM) roasts obtained from bulls and steers fed three levels of dietary roughage (20, 50 and 80 percent alfalfa-brome hay) were determined. Evaluations were conducted by dry heat roasting at 121°C and 163°C to 63°C internal temperature. Cooking losses of SM roasts were affected by cooking temperature, but not by level of dietary roughage or castration. Subjective evaluation by a trained panel indicated that SM roasts cooked at 121°C were significantly better in texture, softness, juiciness, flavor, tenderness, residual connective tissue and overall acceptability than comparable samples cooked at 163°C. Objective measurements of juiciness (water holding capacity) and tenderness for SM roasts supported the findings from sensory evaluations. Trained panelists indicated that SM roasts from animals on all roughage levels were similar in eating quality. There were no significant differences in water holding capacity (WHC), Warner Bratzler shear and penetrometer data attributable to roughage levels; Ottawa Texture Measuring System (OTMS) data indicated that samples from the 20 percent roughage group were more tender than those from the 80 percent roughage group. SM roasts from steers were subjectively rated significantly better in texture, tenderness and connective tissue than comparable samples from bulls; roasts from both “sexes” were similar in all other quality characteristics evaluated. Roasts from bulls had a greater WHC than those of steers. There were no significant differences in Warner Bratzler shear force values and penetrometer data attributable to sex; OTMS data indicated that SM roasts from steers were more tender (P

Influence of Rapeseed Meal on the Odor and Flavor of Eggs from Different Breeds of Chickens

Abstract Experiments were conducted to study the effects of breed or strain of hen, level of rapeseed meal (RSM) in the rations and the presence of a source of myrosinase in the ration on the incidence of off-odor and off-flavor in eggs. A trained panel evaluated scrambled eggs using the multiple comparison method. In Experiment 1, Shaver White Leghorn (WL) pullets were fed rations containing regular RSM, low glucosinolate RSM or a control ration. In Experiment 2, White Plymouth Rock (WPR) pullets were fed rations containingB napusRSM,B napusRSM plus a source of myrosinase or a control ration. In Experiment 3, three breeds of pullets (Hyline WL.Rhode Island Red (RIR) and WPR) were fed rations containing regular RSM, regular RSM plus a source of myrosinase or a control ration. Results obtained indicate that: 1. Differences in the incidence of off-odor and off-flavor in scrambled eggs attributable to breed were found. In this regard, RIR fed a diet containing 6.8% RSM layed eggs with off-odor and off-flavor, whereas, WPR and WL fed the same diet layed eggs of normal odor and flavor. 2. Inclusion of a source of myrosinase in rations containing RSM seemed to increase the incidence of laying of eggs with off-odor and off-flavor.

Efficacy of tertiary butylhydroquinone on the storage and heat stability of liquid canola shortening

The sensory (odor and flavor) and physicochemical characteristics of tertiary butylhydroquinone (TBHQ) treated and butylated hydroxyanisole/toluene (BHA/BHT) treated liquid canola shortenings, subjected to accelerated storage (Schaal oven test at 65°C) and deep fat heating (at 185°C), were determined. Data for the Schaal oven test indicate that TBHQ was effective in retarding oxidative rancidity in liquid canola shortenings. However, addition of the commonly used mixture of BHA/BHT to canola shortenings resulted in only a slight decrease in oxidation during schaal oven storage. The results obtained from deep fat heating of canola liquid shortening show that neither TBHQ nor BHA/BHT was effective in enhancing oxidative and thermal stability of this product.

Taste perception and breast cancer: Evidence of a role for diet

Suprathreshold taste perception and nutrient intake were assessed for two groups of women aged 44 to 56 years: 24 mastectomized breast cancer outpatients and 24 matched controls. Salty and sweet taste intensity and pleasantness were evaluated in aqueous solutions and simple foods by unstructured line scaling. Dietary intakes were assessed by combined dietary recall (1 day) and food record (3 days). Suprathreshold taste intensity and pleasantness data did not differ between the breast cancer and control groups. Breast cancer subjects consumed less energy and were at greater overall nutritional risk than the controls. Compared with control subjects, breast cancer subjects were at greater risk of calcium and iron deficiency. Regression analysis was used to investigate relationships between diet and taste for a breast cancer subgroup (n = 7) with unusually low energy intake (< or = 1,300 kcal/day) and a high overall nutritional risk (25.6%). For the subgroup, significant relationships between taste and diet were found, although taste data did not differ from that of the controls. Percent risks of nutrient deficiency for vitamin B-12, thiamin, folacin, iron, and riboflavin were important predictors of taste-intensity slopes for the cancer subgroup. Findings suggest that for some of the breast cancer subjects, diet may be associated with unsatisfactory nutritional status and may be affected by suprathreshold taste perception.

The Effect of Conventional and Microwave Cooking on the Eating Quality of Beef from Bulls of Three Differing Breed-Types

Abstract The effects of microwave cooking with intermittent energy application and of conventional electric heating on the cooking losses and eating quality of paired beef semitendinosus (ST) roasts were determined. The beef was obtained from young bulls, representing three breed-types: Hereford crossbred (HC), dairy crossbred (DC) and beef synthetic (SY), which had been fed and managed under similar conditions. Cooking time and cooking losses of ST roasts were affected by cooking method, but did not appear to be affected by breed. Subjective evaluation indicated that roasts from both cooking methods were similar in internal color, initial juiciness, softness, juiciness, flavor, residual connective tissue and overall acceptability but panelists rated roasts cooked conventionally significantly better in external color, evenness of internal color, texture and tenderness than those cooked electronically. Objective measurements of juiciness (water holding capacity (WHC), tenderness (Warner Bratzler shear, Ottawa texture measuring system (OTMS) with Warner Bratzler blade) and softness (penetrometer) for ST roasts agreed with findings for cooking method from sensory evaluations. Trained panelists indicated that ST roasts from all breeds were similar in eating quality. There were no significant differences in WHC, Warner Bratzler shear values. OTMS measurements and penetrometer data attributable to breed. Thus, these studies suggest that 1) ST roasts may be cooked using either conventional electric ovens or microwave ovens operated with intermittent energy application; and 2) beef obtained from the three breed-types of young bulls was similar and judged acceptable in eating quality.

Studies of extra low voltage electrical stimulation of mature beef carcasses

The quality characteristics of biceps femoris (BF) and semimembranosus (SM) roasts obtained from mature cow carcasses treated with a commercial extra low voltage (30 V) electrical stimulation (LVES) system were determined. LVES was applied for either 2 (ESII) or 4 min (ESIII). Evaluations were conducted on meat obtained from control sides (no ES) aged for either 48 h (Ia) or 7 days (Ib) and from ES sides aged 48 h. ES caused a reduction (P<0·001) in pH values at 2 and 6 h post mortem. At 24 h, the pH of muscles from all carcasses was about 5·5. ES duration did not influence muscle pH. Rib-eye muscle colour for ESII and ESIII carcasses was lighter and brighter (P<0·05) than that of control carcasses. Generally stimulated BF roasts had greater cooking losses than control Group Ib roasts; SM roasts from ES carcasses had lower losses than comparable to Group Ib roasts. ES duration had no effect on per cent cooking losses. Trained panelists generally detected few significant effects in BF roasts due to ES. Warner-Bratzler data indicated that ESII and ESIII BF roasts were similar and significantly more tender than comparable control Group Ib samples: OTMS data indicated that all BF roasts were similar in tenderness. However, SM roasts from ES carcasses were judged more soft (Groups II and III) and tender (ESII) than comparable control roasts. Instrumental measurements of tenderness for SM roasts tended to support the taste panel results. Generally, duration of LVES had no effect on the eating quality of either BF or SM roasts. Since LVES effects on the palatability of SM roasts were evident but the effects of stimulation of BF roasts were few, further studies of this LVES system are needed before its use can be recommended. Generally, increasing post-mortem ageing time for mature control carcasses did not influence either BF or SM roast quality.