Food Chemistry Commons^™

Effects Of Critical Environmental Factors On The Antimicrobial Activity Of Ε-Poly- L-Lysine, Zhenjie Liu, Peihao Huang, Shu Chen, Shun Rong, Feiting Peng, Ling Chen, Weipeng Guo

Journal of Food Science and Biotechnology

[Objective ] This study explored the effects of critical environmental factors [water activity (aw),pH,and temperature ] on the antimicrobial activity of ε-poly- L-lysine (ε-PL),aiming to provide a basis for the application of ε-PL.[Method ] With Staphylococcus aureus as an indicator strain,the micro-broth dilution and agar dilution methods as well as antimicrobial growth kinetics were utilized to determine the antimicrobial activity of ε-PL.The protein leakage assay was employed to evaluate the bacterial membrane disruption activity of ε-PL.Live/Dead fluorescence staining was performed to observe the bacterial membrane permeability.[Result ] The minimum inhibitory mass concentration (MIC ) of ε-PL against Staphylococcus aureus was …

Microbiological And Physicochemical Changes In Rabbit Meat During Ambient Storage, Marielle Gamboa, Dennis Marvin Santiago, April Shayne Sulabo, Mary Ann Torio

The Philippine Agricultural Scientist

This study aimed to evaluate the changes in rabbit meat during storage at ambient temperature (30 ± 1ºC) for nine hours. The study focused on two rabbit muscle parts: the hind leg and the saddle, investigated in terms of microbiological parameters such as aerobic plate count (APC) and total coliform count (TCC); and physicochemical parameters such as pH, color, total myoglobin concentration, and lipid oxidation. Data obtained were subjected to statistical analysis at a 5% significance level (p < 0.05). Results revealed that the pH of both portions of rabbit muscle decreases over time during storage. This decrease is attributed to the growth of acid-producing microorganisms, which ultimately leads to spoilage in rabbit meat. On the contrary, color values (L*, a*, and b*) showed an increasing trend in both muscle portions, indicating a discoloration of rabbit meat during storage. Both lipid oxidation and total myoglobin content of rabbit meat did not change significantly during storage, but lipid oxidation varied between muscle parts. Based on the microbiological analysis of rabbit meat, both aerobic plate count (APC) and total coliform count (TCC) increased significantly during storage in both muscle portions. Results of the study suggest that freshly slaughtered rabbit meat must remain at ambient storage for the shortest time, as this storage condition will cause spoilage of meat, making it unfit for human consumption.

Gut Community Response To Wheat Bran And Pinto Bean, Shuen Leow

Department of Food Science and Technology: Dissertations, Theses, and Student Research

There is general consensus among the scientific community that dietary fibers reduce the risk of Western diseases through their fermentation by beneficial microbial communities in the human gut. However, dietary fibers in wheat bran (WB) and pinto bean (PB) are incompletely fermented by the gut microbiota. Therefore, there is a critical need to identify gut microbial communities that can increase fermentation of dietary fibers from these foods to maximize their disease-preventing properties. The goal of this study was to identify such communities with increased capacity to ferment the dietary fibers in WB and PB. To accomplish these goals, a stepwise …

Lowering Greening Of Cookies Made From Sunflower Butter Using Acidic Ingredients And Effect On Reducing Capacity, Tryptophan And Protein Oxidation, Sihui Liang, Hanh Lan Tran, Lilian Were

Food Science Faculty Articles and Research

Lowering of greening formed from oxidized chlorogenic acid (CGA) and amino groups, and favoured at alkaline pH, was investigated using acidic ingredients (sour cream, buttermilk, yoghurt, and honey) in sunflower butter cookies. Cookies with maple syrup added were used as a positive control. Changes in greening intensity, greening reactants (total phenols, CGA, protein), antioxidant capacity, tryptophan and Schiff base fluorescence were measured. Percentage greening, pH and aw of cookies followed the same order: maple syrup> sour cream ≥ buttermilk> yoghurt> honey. pH was positively correlated with greening intensity (r=0.77) and negatively correlated with CGA (r=-0.96). Total phenolic content, antioxidant capacity, …

Chlorogenic Acid Oxidation-Induced Greening Of Sunflower Butter Cookies As A Function Of Different Sweeteners And Storage Conditions, Sihui Liang, Lilian Were

Food Science Faculty Articles and Research

Sunflower butter use as an allergen-free alternative to tree and legume nut butter in baking is limited by chlorogenic acid induced greening that occurs at alkaline pH. Limited information is available on controlling this greening in a food matrix. This study examined how different liquid sweeteners and relative humidity influenced greening of sunflower butter cookies. Doughs had similar initial pH (7.52–7.66) which increased to 8.44–9.13 after baking as ranked: xylitol > maple syrup > corn syrup > honey > agave syrup. Cookies made with maple syrup had the highest moisture and greening corresponding with lowest free chlorogenic acid. The % greening followed the same …

Influence Of Sodium Chloride, Calcium, Moisture, And Ph On The Structure And Functionality Of Nonfat Directly Acidified Mozzarella Cheese, Brian M. Paulson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Experiment A explored the influence of sodium on direct acid, nonfat Mozzarella cheese. Cheeses with differing salt levels were obtained by varying dry salt applications (none, 0.5%, and 1.0% NaCl w/w) and hot brine stretching (0%, 5%, and 10% NaCl wt/v). Salt application and salt content influenced cheese moisture, meltability, expressible serum, micro- and ultra-structure, and color. Moisture was highest when cheese was salted before stretching (P = 0.03). Melt was lowest in cheeses that were unsalted (P = 0.05). Cheeses stretched in salt brine had < 1% of the amount of expressible serum found in unsalted cheese (P < 0.0001). Unsalted cheeses had a more open structure with pockets of serum distributed throughout the protein matrix giving it an opaque, white appearance. Salted cheeses had a more homogeneous protein matrix lacking light scattering surfaces, resulting in a translucent cheese. Neither salt concentration nor method of salting affected the calcium content of the cheeses (P > 0.05).

Experiment B explored the influence of calcium, moisture, and …

Effect Of Ph, Fat Level, And Various Browning Agents On Composition, Color, Texture, And Sensory Characteristics Of Dark-Cutting Beef Patties, Igor V. Moiseev

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Extra lean (3.3% fat) and lean (20.0% fat) hamburgers in three pH groups (≤ 6.0; 6.01-6.49; 6.50-6.92) were evaluated for cooking-temperature profile, total process lethality, and physical properties after cooking to 71°C by double-side frying on an electric grill. Neither cooking-temperature profile nor cooking time was affected by hamburger fat content or pH. Double-side frying to 71.1°C internal temperature was adequate for more than 6-log destruction of viable E. coli O157:H7 and Salmonella at the geometrical center of extra lean and lean hamburgers. The coldest spot was on the circumferential surface, as indicated by the presence of a red ring …