David W Everett | California Polytechnic State University at San Luis Obispo (original) (raw)

Papers by David W Everett

Food and Bioproducts Processing, 2016

Advances in experimental medicine and biology, 1995

AGRIS record. Record number, US9566403. Titles, Applications of confocal microscopy to fat globul... more AGRIS record. Record number, US9566403. Titles, Applications of confocal microscopy to fat globule structure in cheese. Personal Authors, Everett, DW (University of Wisconsin, Madison, WI.),Ding, K.,Olson, NF,Gunasekaran, S. Publication Date, (1995). AGRIS Subj. Cat. ...

Food Chemistry, 2014

The encapsulation of green tea catechin and epigallocatechin gallate (EGCG) in soy lecithin lipos... more The encapsulation of green tea catechin and epigallocatechin gallate (EGCG) in soy lecithin liposomes was examined at four concentrations (0%, 0.125%, 0.25% and 0.5% w/v), and inclusion in cheese at 0% and 0.25% w/v. The empty capsules had a mean diameter of 133 nm and significantly (p < 0.05) increased with the addition of catechin or EGCG. Electron microscopy revealed the lamellae and central core of the liposomes. Addition of antioxidants gave a significant (p < 0.05) increase in the size of liposomes. Liposomes had surface potentials of À42.4 to À46.1 mV with no significant difference between treatments, suggesting stable liposome systems. High efficiency (>70%) and yield ($80%) were achieved from the incorporation of catechin or EGCG inside the liposome structure. Addition of either antioxidant increased the liposome phase transition temperature (>50°C). Nanocapsules containing these antioxidants were effectively retained within a low-fat hard cheese, presenting a simple and effective delivery vesicle for antioxidants.

LWT - Food Science and Technology, 2015

Please cite this article as: Rashidinejad, A., Birch, E.J., Sun-Waterhouse, D., Everett, D.W., To... more Please cite this article as: Rashidinejad, A., Birch, E.J., Sun-Waterhouse, D., Everett, D.W., Total phenolic content and antioxidant properties of hard low-fat cheese fortified with catechin as affected by in vitro gastrointestinal digestion,

International Journal of Food Science & Technology, 2013

The effect of (+)-catechin on total phenolic content (TPC) and antioxidant properties in low-fat ... more The effect of (+)-catechin on total phenolic content (TPC) and antioxidant properties in low-fat hard cheese were examined over a 90-day ripening period at 8°C. Antioxidant activity (AA) in cheese was measured by ferric reducing antioxidant power, oxygen radical absorbance capacity (ORAC) and 2,2diphenyl-1-picrylhydrazyl assays and compared with TPC. Catechin retention coefficients in cheese curds were in the range of 0.63-0.75 and decreased the pH of cheese without affecting protein, fat or moisture content. Both TPC and AA increased during the 90-day ripening period. Oxygen radical absorbance capacity was the most suitable technique for evaluating AA in cheese due to the high correlation with TPC and suitability in both lipophilic and hydrophilic systems. Catechin activity in ripening cheese A. Rashidinejad et al. 2 Catechin activity in ripening cheese A. Rashidinejad et al. Catechin activity in ripening cheese A. Rashidinejad et al. Catechin activity in ripening cheese A. Rashidinejad et al. Catechin activity in ripening cheese A. Rashidinejad et al. Catechin activity in ripening cheese A. Rashidinejad et al.

Page 1. 7 Microstructure of Natural Cheeses DW Everett 7.1 Introduction Milk is a low-acid and hi... more Page 1. 7 Microstructure of Natural Cheeses DW Everett 7.1 Introduction Milk is a low-acid and high-moisture food product and, as a consequence, deteriorates rapidly unless preservation measures are taken. The manufacture ...

Food chemistry, Jan 15, 2016

Thermodynamics of milk components (milk fat, xanthine oxidase, caseins and whey proteins) in puls... more Thermodynamics of milk components (milk fat, xanthine oxidase, caseins and whey proteins) in pulsed electric field (PEF)-treated milk were compared with thermally treated milk (63°C for 30min and 73°C for 15s). PEF treatments were applied at 20 or 26kVcm(-1) for 34μs with or without pre-heating of milk (55°C for 24s), using bipolar square wave pulses in a continuous mode of operation. PEF treatments did not affect the final temperatures of fat melting (Tmelting) or xanthine oxidase denaturation (Tdenaturation), whereas thermal treatments increased both the Tmelting of milk fat and the Tdenaturation for xanthine oxidase by 2-3°C. Xanthine oxidase denaturation was ∼13% less after PEF treatments compared with the thermal treatments. The enthalpy change (ΔH of denaturation) of whey proteins decreased in the treated-milk, and denaturation increased with the treatment intensity. New endothermic peaks in the calorimetric thermograms of treated milk revealed the formation of complexes due t...

Journal of Food Composition and Analysis, 2016

Food & function, Jan 13, 2016

(+)-Catechin or green tea extract were encapsulated in soy lecithin nanoliposomes and incorporate... more (+)-Catechin or green tea extract were encapsulated in soy lecithin nanoliposomes and incorporated into a full-fat cheese, then ripened at 8 °C for 90 days. Cheese samples were subjected to simulated gastrointestinal digestion to measure total phenolic content (TPC) and antioxidant activity of the cheese digesta, and to determine the catechin recovery after digestion by high performance liquid chromatography (HPLC). Addition of catechin or green tea extract significantly (P ≤ 0.05) increased TPC and antioxidant activity (measured by ferric reducing antioxidant power and oxygen radical absorbance capacity) of the full-fat cheese without affecting pH or proximate composition. HPLC analysis confirmed retention of encapsulated catechins in the cheese curd; however, individual catechins were recovered in differing amounts (15-52%) from cheese digesta after 6 h of digestion. Transmission electron microscopy and Fourier transform infrared spectroscopy provided evidence for association of nanoliposomes with the surface of milk fat globules inside the cheese matrix. The study shows the potential for using cheese as a delivery vehicle for green tea antioxidants.

Food chemistry, Jan 15, 2017

Molecular integrations between green tea catechins and milk fat globules in a cheese matrix were ... more Molecular integrations between green tea catechins and milk fat globules in a cheese matrix were investigated using solid-state magic angle spinning nuclear magnetic resonance spectroscopy. Full-fat cheeses were manufactured containing free catechin or free green tea extract (GTE), and liposomal encapsulated catechin or liposomal encapsulated GTE. Molecular mobility of the carbon species in the cheeses was measured by a wide-line separation technique. The (1)H evolution frequency profile of the (13)C peak at 16ppm obtained for the control cheese and cheeses containing encapsulated polyphenols (catechin or GTE) were similar, however, the spectrum was narrower for cheeses containing free polyphenols. Differences in spectral width indicates changes in the molecular mobility of --CH3- or -C-C-PO4- species through hydrophobic and/or cation-π associations between green tea catechins and cheese fat components. However, the similar spectral profile suggests that encapsulation protects chees...

Antioxidants (Basel, Switzerland), 2016

(+)-Catechin, the representative catechin in green tea, was incorporated into a full-fat cheese (... more (+)-Catechin, the representative catechin in green tea, was incorporated into a full-fat cheese (at 125-500 ppm) followed by ripening for 90 days at 8 °C and digesting for six hours. Determination of pH, proximate composition, total phenolic content (TPC) and antioxidant activity (AA) after manufacture and ripening demonstrated that the addition of (+)-catechin significantly (p ≤ 0.05) decreased the pH of both whey and curd during cheese manufacturing and ripening with no significant (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 0.05) effect on the moisture, protein and fat contents. (+)-Catechin increased TPC, as well as AA, though the increase was not proportional with increasing the concentration of added (+)-catechin. About 57%-69% of (+)-catechin was retained in the cheese curd, whereas about 19%-39% (depending on the concentration) was recovered from the cheese digesta. Transmission electron micrographs showed that the ripened control cheese had a homogeneous pattern of milk fat globules with regular spacing entrapped in a homogenous structure of casein proteins, whereas the addition of (+)-catechin disrupted this homogenous structure. The apparent interaction between (+)-catechin and cheese fat globules was confirmed by Fourier transform infrared spectroscopy. These associations should be taken into account when incorporating antioxidants, such as (+)-catechin, to create functional dairy products, such as cheese.

ABSTRACT The utilisation of β-carotene in food and beverage products is limited due to their poor... more ABSTRACT The utilisation of β-carotene in food and beverage products is limited due to their poor water solubility, chemical instability and low bioavailability. Microemulsions are of particular interest as colloidal delivery systems because of the possibility of enhancing the solubility and improving the bioavailability of hydrophobic compounds. However, these systems have not been widely used in the food industry because of the difficulties in their formulation using edible oils and surfactants. The purpose of this study was to compare the pseudo-ternary phase diagram of β-carotene microemulsion prepared using long chain length fatty acids (vegetable oils) and medium chain length fatty acids (Caprylic/Capric triglyceride). The solubility of β-carotene was measured by reversed-phase liquid chromatography (HPLC). The solubility of β-carotene in long chain triglycerides was higher than medium chain triglyceride. Among Tweens that were screened, Tween 80 exhibited the highest solubilizing potential for β-carotene. However, the microemulsion region of a ternary phase diagram containing medium chain triglycerides (Captex 355) was larger than for long-chain length fatty acids (vegetable oils) when Tween 80 was used as surfactant. This study suggests that, due to the difficulty of using vegetable oils in microemulsion formulations, emulsion system composed of medium chain triglyceride such as Captex 355 could be used to prepare food grade β-carotene microemulsion.

International journal of food sciences and nutrition, Jan 9, 2016

Due to their well-known health benefits, green tea catechins have received recent attention as na... more Due to their well-known health benefits, green tea catechins have received recent attention as natural additives in foods such as dairy products. However, they may present some irreversible associations with milk components (e.g. protein and milk fat globules). To investigate the behaviour of two important green tea catechins, (+)-catechin (C) and (-)-epigallocatechin gallate (EGCG), in a standard whole milk system under the conditions of cheesemaking, 250 and 500 ppm of each catechin were added to whole milk (3.3% fat). Although both C and EGCG at either concentration increased both total phenolic content and total antioxidant capacity of the subnatants obtained from the milk system, there was a less linear increase when the concentration of the catechins was doubled, whereas C or EGCG were recovered (measured by HPLC) differently. Overall, these results suggest a degree of associations between green tea catechins with milk proteins and milk fat.