Next Article in Journal
Effect of Buckwheat Groats Processing on the Content and Bioaccessibility of Selected Minerals
Previous Article in Journal
Quality Characteristics of Healthy Dry Fermented Sausages Formulated with a Mixture of Olive and Chia Oil Structured in Oleogel or Emulsion Gel as Animal Fat Replacer
Previous Article in Special Issue
Applicability of Confocal Raman Microscopy to Observe Microstructural Modifications of Cream Cheeses as Influenced by Freezing
Open AccessArticle

Effect of Black Tea Infusion on Physicochemical Properties, Antioxidant Capacity and Microstructure of Acidified Dairy Gel during Cold Storage

1
Department of Wine, Food and Molecular Biosciences, Lincoln University, Lincoln 7647, New Zealand
2
Department of Food, Bioprocessing and Nutrition Sciences, Southeast Dairy Foods Research Center, North Carolina State University, Raleigh, NC 27695, USA
3
Dairy Innovation Institute, California Polytechnic State University, San Luis Obispo, CA 93407, USA
4
Tea Science Department, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
5
School of Food Science of Engineering, South China University of Technology, Guangzhou 510641, China
*
Authors to whom correspondence should be addressed.
Foods 2020, 9(6), 831; https://doi.org/10.3390/foods9060831
Received: 9 April 2020 / Revised: 19 June 2020 / Accepted: 22 June 2020 / Published: 25 June 2020
(This article belongs to the Special Issue Chemical and Technological Characterization of Dairy Products)
The impacts of black tea infusion on physicochemical properties, antioxidant capacity and microstructure of stirred acidified dairy gel (ADG) system have not been fully explored. These impacts were studied during a 28-day cold storage (4 °C) period to explore the feasibility and technical boundaries of making acidified dairy gels in which black tea infusion (BTI) is incorporated. Reconstituted skim milks containing different proportions of BTI were acidified by GDL (glucono-δ-lactone) at 35 °C for making ADG systems. Both textural properties and structural features were characterized; antioxidant capacity was determined through three assays. They are (1) free radical scavenging ability by DPPH (2,2-diphenyl-1-picrylhydrazyl) assay; (2) ABTS [2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid)] assay and (3) ferric reducing antioxidant power (FRAP) assay. The microstructure of the ADGs was observed using SEM (scanning electron microscopy) and CLSM (confocal laser scanning microscopy). Results showed that BTI significantly increased the antioxidant capacity of the gel systems and the gel containing 15% BTI was as stable as the control gel in terms of syneresis rate. However lower phase stability (higher syneresis rate) was observed in the ADG with a higher portion of BTI (30% to 60%). The microstructure of the ADGs observed may explain to the phase stability and textural attributes. The results suggested that tea polyphenols (TPs) improved antioxidant capacity in all samples and the interactions between BTI and dairy components significantly altered the texture of ADGs. Such alterations were more pronounced in the samples with higher proportion of BTI (60%) and/or longer storage time (28 days). View Full-Text
Keywords: black tea; acidified dairy gel; textural property; antioxidant capacity; microstructure black tea; acidified dairy gel; textural property; antioxidant capacity; microstructure
Show Figures

Figure 1

MDPI and ACS Style

Chen, H.; Zheng, H.; Anne Brennan, M.; Chen, W.; Guo, X.; Brennan, C.S. Effect of Black Tea Infusion on Physicochemical Properties, Antioxidant Capacity and Microstructure of Acidified Dairy Gel during Cold Storage. Foods 2020, 9, 831.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Search more from Scilit
 
Search
Back to TopTop