<p> Both epidemiological and clinical evidence support the notion that polyphenol rich foods and beverages may modify glycemic response, glucose homeostasis and subsequent risk of Type-2 diabetes. <i>In vitro</i> evidence typically derived from experiments with pure phenolics and phenolic rich extracts have pointed to this benefit being associated with two potential mechanisms: (1) the ability of specific polyphenolics to inhibit carbohydrate digestion (amylase and glucosidase) and (2) polyphenolic inhibition of intestinal glucose transport. While the high potential of these activities is evident, little is actually known regarding the extent to which these benefits are extendable to the actual food matrix these phenolics are naturally present in. Further, the extent to which co-consumption of polyphenol rich foods may actually result in decreased glycemic response from a mixed meal remains mostly unknown. Considering these limitations, additional insights are required in order to advance knowledge on the benefits of polyphenolics on glucomodulatory mechanisms and translation of these insights into meaningful recommendations and products for consumers. With this in mind, the objectives of these studies were to determine the extent to which phenolic-rich foods (grapes and potatoes) exert glucomodulatory properties in model food systems using <i>in vitro </i> and <i>in vivo</i> assessments. First, mechanisms associated with polyphenol rich extracts or model foods on carbohydrate intestinal digestion and glucose transport were investigated <i>in vitro</i> using a three-stage <i>in vitro</i> digestion model coupled to the Caco-2 human intestinal cell model. Components of this model used individually or in combination allowed for assessment of the two main mechanistic steps in phenolic modulation of glycemic response (starch digestion and glucose transport) in the context of interactions with bioaccessible phenolics. Additionally, the ability of the coupled <i>in vitro</i> digestion/Caco-2 model to predict <i>in vivo</i> outcomes was assessed.</p><p> The first study compared the ability of 100% Niagara or Concord grape juice (GJ) phenolics to modify carbohydrase activity and intestinal glucose transport relative to a sugar sweetened beverage. While grape juices remain a major dietary source of phenolics, they are also well recognized to be naturally high in sugar content. Insights into the ability of natural fruit phenolics to modify glycemic response of grape juice were investigated <i>in vitro. </i> Also, in consideration that 100% GJ is consumed with meals, the extent to which modulation of carbohydrate digestion and intestinal absorption by GJ phenolics can be extended to a carbohydrate rich meal was evaluated. In the first experiment, inhibition of &alpha;-amylase and &alpha;-glucosidase by GJ extracts (300 and 500 &mu;M total phenolics) and ability of GJ extracts (10 to 100 &mu;M total phenolics) to modulate labelled glucose and fructose transport across Caco-2 intestinal cell monolayers compared to a phenolic-free control were determined. GJ extracts decreased &alpha;-glucosidase, but not &alpha;-amylase activity at both concentrations tested. Further, glucose and fructose transport were significantly (p&lt;0.05) decreased in a dose-dependent manner by Niagara and Concord GJ extracts. In a second experiment, GJs and phenolic-free control beverages were co-digested <i>in vitro</i> with a starch-rich model meal. Resulting aqueous digesta (AQ) from both experiments were used to assess impact of bioaccessible GJ phenolics on carbohydrate digestion and glucose transport. Concord and Niagara GJs significantly decreased <i>in vitro </i> gastrointestinal digestion of carbohydrate from model meal compared with a sugar-matched control. Further, d7-glucose transport from AQ fraction of GJ and co-digested GJ and carbohydrate-rich meal across Caco-2 human intestinal cell monolayers was significantly decreased compared to phenolic-free sugar-sweetened control.</p><p> The second study evaluated potential for phenolics from starch rich white, purple, or red potatoes to modulate carbohydrate digestion or glucose transport in a Caco-2 intestinal cell model. Potato phenolic extracts (300 &mu;M) had no impact on &alpha;-amylase activity, and marginally decreased &alpha;-glucosidase activity. However, potato phenolic extracts (25-100&mu;M) did decrease d7-glucose transport compared to phenolic-free control. Interestingly, whole potato phenolic extracts reduced glucose transport to a greater extent compared to those from potato peel. To determine if results from aforementioned <i>in vitro </i> assays are predictive of effects <i>in vivo</i>, a pilot clinical study (n=11) was completed to assess differences in acute blood glucose response and gastric emptying following consumption of phenolic-rich purple and red potato chips compared to white potato chips (50g available carbohydrate) containing lower level of total phenolics. Blood glucose levels were measured for up to two hours. Peak blood glucose levels were lower for pigmented chips, especially purple chips, compared to white chips without any significant changes in gastric emptying. These results suggest that potato phenolics may play a role in modulation of intestinal glucose transport and that these effects are translatable to consumer products such as potato chips.</p><p> Taken together, these data support the notion that phenolics intrinsic to select foods have the ability to modify glycemic response through alteration of glucose transport and to a certain extent starch digestion. Therefore, it is likely that observed benefits associated with consumption of phenolic-rich foods and 100% fruit juices, as a part of an overall healthy diet, may be associated with the ability of intrinsic and bioaccessible phenolics to modify glycemic response. Future research that focuses on hypoglycemic effects of phenolic-rich foods should be larger scale and should evaluate a greater variety of phenolic-rich foods in order to better understand the extent to which phenolic class and food matrix impact hypoglycemic effects. Regarding meal-effects, a pilot clinical study should be completed to validate <i>in vitro</i> results and to provide information as to what degree various types of meal patterns alter glycemic effects of phenolic-rich foods. Such information can be leveraged in the development of phenolic-rich food products that have post-prandial glycemic effects and for making recommendations of dietary choices which may result in improved glucose homeostasis.</p>

Catfish skin (CS) contains considerable amount of protein that may be hydrolyzed enzymatically to generate hydrolysates (CSH) which may have antioxidant and antimicrobial properties. The generation of natural compounds with these properties is of special interest to the food industry. The objective of this study was to develop and characterize CSH including antioxidant and antimicrobial properties. CSH were produced from different enzymatic reaction periods using alkaline protease, and their characterization, antioxidant, antimicrobial, and some functional properties were evaluated. A selected CSH was analyzed for peptide composition and partial amino acid sequences. The color analysis showed that darker, more yellow, and redder CSH were generated throughout the time of hydrolysis. CSH at 4, 5, and 6 h of hydrolysis showed considerable antioxidant activity and antimicrobial properties in-vitro, high emulsion stability, and low oil holding capacity influenced by the time of hydrolysis. Low-molecular weight peptides with positive charges were suggested as responsible for the antimicrobial activity. CSH were developed and characterized. Further research is suggested, especially on identification, isolation, and synthesis of specific peptides from CSH with both antioxidant and antimicrobial activity.

A written objective-type waiver examination for the introductory foods course at Utah State University has been developed and evaluated. Results of the study showed that the examination improved with revision. In addition, it was found that there was a statistically significant relationship between the score students achieved on the waiver examination and the total numerical score representing the final grade in the basic foods course. There was apparently no significant relationship between the number of years experience students had in food preparation, the type of experience in food preparation, and their performance on the waiver examination. Apparently depth of knowledge of basic food preparation principles was a more important factor than just years or breadth of experience (skill) in contributing to the waiver examination score. The waiver examination has been adopted for use by the Department of Food and Nutrition at Utah State University. Recommendations are made regarding use of the examination and the possible need for re-evaluation of the curriculum for introductory foods work.

Master of Science / Food Science Institute - Animal Sciences & Industry / Sara E. Gragg / Food preparation in institutional settings is often carried out in large quantities. Food is cooked and then cooled and stored for later service. Improper or "slow" cooling has been identified by the United States Food and Drug Administration (US FDA) as a contributing factor in foodborne illness outbreaks. This study was designed to test the efficacy of cooling technique combinations on controlling microbial growth within pre-cooked taco meat, chili con carne with beans, low sodium marinara sauce, and brown rice food products. These products were cooked to 73.8°C (165°F) and then portioned to 2 and 3-inch depths in steam table pans. Food product was allowed to cool to 60°C ± 5°C (140°F ± 5°F) before inoculation with surrogate Escherichia coli (E. coli) or Biosafety Level I (BSL I) Bacillus cereus (B. cereus). Pans were uncovered or covered with one or two layers of aluminum foil to allow or restrict air exposure and then placed in a -20°C (-4°F) commercial walk-in freezer or situated in ice water baths in a commercial walk-in refrigerator 4°C (39.2°F). Food products were sampled over a 24-hour period (0, 4, 8, 12, and 24 hour time points) for enumeration of microbial populations. Conclusions from the cooling temperature data in this study revealed uncovered pans and pans stored in the freezer at 2-inch food product depths cooled most rapidly. However, few cooling methods achieved the two-step US FDA Food Code requirement for pre-cooked taco meat, chili con carne with beans, and brown rice products and none of the cooling methods tested achieved the US FDA food code requirement for low sodium marinara sauce. Surrogate E. coli and BSL I B. cereus microbial population data revealed pre-cooked taco meat, chili con carne with beans, and brown rice products all exhibited a certain degree of overall population decline during the 24-hour cooling period. However, a small recovery of surrogate E. coli population was observed in the low sodium marinara sauce product as well as 2-inch product depths of the chili con carne with beans product. This observed growth was less than 0.50 log₁₀ CFU/g, indicating low risk for microbial proliferation from the cooling methods tested. It is possible that the surrogate E. coli and BSL I B. cereus population changes observed were not the result of cooling failure or risk, but rather due to natural variations within the food products. These results indicate all 12 cooling methods tested were low risk and therefore effective at controlling E. coli and B. cereus microbial populations within the four food products.

Contaminated surface water is a potential source of microbial contamination in fruits and vegetables. Fruits and vegetables producers using surface water as irrigating crops need irrigation water treatments that do not leave any chemical residue in the water. This work evaluated the efficacy of ultraviolet (UV)-C light on pathogen risk reduction from surface water used for irrigation of cantaloupes in an agricultural setting. Replicated cantaloupe plots (12 plots, 3/treatment, plot size 5x15, 10 plants/plot) were irrigated (spray or drip irrigation) with UV-C light-treated or non-treated water. A mixture of pond and well water (1000 L) (UV transmittance rate 53.74±2.12) collected in a tank was inoculated with a cocktail of generic &i;E. coli&/i; (ATCC 23716, 25922, and 11775). The inoculated water (7.4 log most probable number, MPN/100 ml) was then treated with UV-C light doses (16 to 120 mJ/cm&178;) by passing through a UV-C treatment unit PMD 150C1/4. Significant reduction (P< 0.05) of generic &i;E. coli&/i; (>3 log MPN/100 ml) was achieved with lower doses of UV-C light (10-20 mJ/cm&178;) and below the detectable limit of the test for UV-C doses above 50-60 mJ/cm&178;. The generic &i;E. coli&/i; counts on cantaloupe irrigated with UV-C light-treated or non-treated water were similar (3.30±0.12 and 3.39±0.14 log MPN/cantaloupe). Cantaloupe harvested from drip-irrigated plots were significantly lower in counts (2.72±0.12 log MPN/cantaloupe) as compared with sprinkle-irrigated plots (3.97±0.15 log MPN/cantaloupe). Within the drip-irrigated treatment plots, cantaloupes harvested next to the drip emitter were higher in counts by at least 1.2 log as compared with cantaloupes further from the drip emitter. In the first trial, a significant die-off of generic &i;E. coli&/i; was observed on cantaloupe surfaces within three days from the last day of irrigation; however, levels were similar for five days in the second trial. Our results indicated UV-C light is an effective antimicrobial treatment for microbial risk reduction of surface irrigation water, but influence on generic &i;E. coli&/i; levels on cantaloupe surface was unclear.

<p> The consumption of added sugars has gained much attention due to its affiliation with increased incidence of type 2 diabetes and associated chronic illnesses. In this study, an ice-cream prototype was developed using whole dried figs and evaluated for overall consumer acceptability (34 subjects) based on flavor and texture, compared to a control using 9- point hedonics (1 = like extremely; 9 = dislike extremely). Overall acceptability of the prototype and consumer awareness of the FDA proposed new nutrition facts label were also evaluated. Significant (P &lt; 0.000) differences were observed between the prototype and control regarding flavor (4.79&plusmn;0.34; 2.35&plusmn;0.19), texture (4.35&plusmn;0.33; 1.94&plusmn;0.16), and overall acceptability (4.94&plusmn;0.35; 2.41&plusmn;0.23) respectively. Furthermore, 88.2% of participants preferred seeing nutrition-related psychographical information on the PDP. It can be concluded that consumers may purchase the prototype based on psychographical information related to health claims and their awareness of the FDA proposed food label.</p>

Bakgrund I dagsläget finns mycket forskning om tarmflorans koppling till vår hälsa, däremot finns begränsat med forskning om hur insatta konsumenter är i frågan. Syfte Syftet med studien var att undersöka människors medvetenhet om tarmflora och om de gör aktiva val för att förbättra sin tarmflora. Metod En kvantitativ metod användes. Data samlades in med hjälp av en webbaserad enkät som spreds på det sociala nätverket Facebook och studentplattformen Cambro. Studien inkluderade personer från 18 år och uppåt. Databearbetning och analys gjordes i programmet IBM SPSS Statistics version 25. Data analyserades genom Chi-2-test och Mann-Whitney U- test. Signifikansnivån sattes till p &lt; 0,05. Resultat I studien deltog 184 personer. De flesta var kvinnor och över hälften av deltagarna hade kostbakgrund. Kvinnor och personer med högskoleutbildning hade signifikant högrekännedom om begreppet ”Probiotika”. Personer med kostbakgrund hade signifikant högre kännedom om begreppen “Goda tarmbakterier”, “Tarmflora”, “Probiotika”, “Prebiotika” och “Synbiotika”. Av deltagarna gjorde 58% aktiva livsmedelsval för att förbättra sin tarmflora.Äldre personer gjorde i större utsträckning livsmedelsval utifrån tarmfloran jämfört med yngre. Den mest använda källan för information om tarmflora var kritiskt granskade internetsidor. Män och personer utan kostbakgrund använde i större utsträckning icke kritiskt granskade internetsidor. Slutsats Studien visar att personer i allmänhet har låg medvetenhet om tarmflora och därmed behöver få mer kunskap om detta där två grupper som det särskilt behöver fokuseras på är män och yngre personer. Dietisten har här en viktig roll i spridandet av kunskap men även att informera om lämpliga informationskällor så att befolkningen ökar sin medvetenhet och kunskap om tarmflora. / Background Today, there is a lot of research about the relationship between intestinal flora and our health, however research about how informed consumers are is limited. Objective The purpose of this study was to investigate peoples’ awareness regarding theintestinal flora and if they make active choices to improve their intestinal flora. Method A quantitative research method was used. Data were collected using a web-based survey that was spread across Facebook and the student platform Cambro. The study included people from 18 years of age and above. Data were analyzed by Chi-2 test and Mann-Whitney U test. Significance level was set to p &lt; 0,05. Results The study involved 184 people. Most of the participants were women and more than half of the participants had a dietary background. Women and participants with a college degree had a higher level of awareness about the concept of probiotics. Participants with dietary background had a higher awareness of all terms related to intestinal flora. In total, 58% of the participants made active food choices to improve their intestinal flora. Older people made to a greater extent active food choices to improve their intestinal flora than younger persons. The most commonly used source of information about intestinal flora was critically reviewed web pages. Men and people without dietary background used to a greater extent non-critically reviewed web pages to find information. Conclusion The study shows that people generally have low awareness about intestinal flora and therefore need to develop their knowledge about this, where men and younger people in particular need to be focused on. The dietitian has an important role to increase the awareness of intestinal flora in the population by spreading knowledge and informing about appropriate sources of information.

Oxidation products of unsaturated fatty acids in foods cause rancid flavor and limit the storage stability of food products. Even though many synthetic antioxidants are used, increasing interest has been directed towards the utilization of normal food constituents having antioxidative properties. / In aqueous lysine-sucrose model systems, the effects of reaction time, pH and molar ratio were studied on the formation of non-enzymatic browning reaction (NBR) products. The extent of sucrose hydrolysis was measured and the antioxidant effect of NBR products on linoleic acid emulsions was examined. Nuclear magnetic resonance (NMR) spectra were obtained at various stages of browning. / Sucrose produced NMR products with lysine in an aqueous system at 100(DEGREES)C. The C-13 NMR spectra indicated that the NBR started when sucrose and lysine were dissolved in water. The C-13 NMR spectra also showed that heating did not have an effect on the gross composition of polymeric species. The absorbance at 480 nm of 0.75 M lysine-sucrose solution heated up to 6 hours increased with reaction times. The pH values of heated lysine-sucrose solution gradually decreased with reaction time. When 0.75 M sucrose or lysine solution was heated separately up to 6 hours, there were no changes in absorbance in pH. In the pH range of 3.52 - 6.35, higher absorbance was obtained from heated lysine-sucrose solution at acidic pH levels than at neutral pH levels. / As the concentration of lysine and sucrose solution was increased, the absorbance increased. At longer reaction times or acidic pH levels, enhanced hydrolysis of sucrose to reducing sugars resulted in more NBR products. NBR products obtained at a longer reaction time, an acidic pH, and higher concentration of reactants showed a darker brown color and were effective in preventing the formation of peroxides. The oxygen uptake of linoleic acid emulsion having NBR products was smaller than that of linoleic acid emulsion without NBR products. Based on these results, it was concluded that sucrose may act as an antioxidant in processed foods containing both amino acids and lipids. / Source: Dissertation Abstracts International, Volume: 48-02, Section: B, page: 0312. / Thesis (Ph.D.)--The Florida State University, 1987.

The effects of nitrogen and potassium fertilization on tomato flavor were studied. Field-grown Walter c.v. tomatoes were treated with three levels of nitrogen and potassium. Soluble solids, pH, titratable acidity (TA), volatile flavor compounds, and sensory evaluation of overall flavor were studied. / Taste panel tests indicated that the lower fertilization level (100 lb/A N- 150 lb/A K) yielded tomatoes with a more desirable flavor. Tomatoes grown at the two higher levels of fertilization (200 lb/A N-300 lb/A K; 300 lb/A N-450 lb/A K) did not differ in flavor. Soluble solids and TA were found to increase with increasing levels of N and K. There was a modest trend toward lower pH values in tomatoes grown at lower fertilization levels. Although no qualitative differences were observed among volatiles from the three treatments, several compounds were found to change quantitatively with treatment. MS and GC enrichment were used to tentatively identify these volatiles. Hexenal, 2-hexanone, 2,4-hexadienal, benzaldehyde, phenylacetaldehyde, beta-ionone and 6-methyl-5-hepten-2-one were found to increase with increasing levels of N and K fertilization. Farnesol isomers appeared maximally in treatment II and eugenol decreased with increasing fertilization. / This study indicates that tomatoes treated with high levels of N and K do not exhibit desirable flavor despite an increase in both TA and soluble solids. This may be due to the intrusion of undesirable flavors from volatiles whose production is increased under conditions of high N and K fertilization. / Source: Dissertation Abstracts International, Volume: 43-10, Section: B, page: 3182. / Thesis (Ph.D.)--The Florida State University, 1982.

Source: Dissertation Abstracts International, Volume: 40-07, Section: B, page: 3077. / Thesis (Ph.D.)--The Florida State University, 1979.