Physiochemical, Proximate Composition and Microbial Quality of a Novel Probiotic Yoghurt Fortified with Purple-Leaf Tea (Camelias Sinensis)
Loading...
Date
2024-12
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
AJFAND
Abstract
With the increasing demand of health promoting food products, formulations of
yoghurts are changing more towards live probiotic starter culture milk fermentation
and fortification with plant-based food ingredients to improve the flavour and nutrition
composition. Synbiotic yoghurts fermented with probiotic microbes and fortified with
prebiotic food ingredients have become very popular as functional foods due to their
scientifically proven bioactive compounds that promote human gut health and
alleviate dysbiosis. The aim of the current study therefore, was to assess the
physiochemical, nutritional proximate composition and viability of probiotics in
formulated yoghurt fortified with a novel purple-leaf tea (Camelias sinensis) puree
that is rich in anthocyanins, bioactive polyphenols. Whole milk was fermented with
probiotic starter culture (Lactobacillus acidophilus (LA-5), Bifidobacterium animalis
subsp. lactis -ABT 5) from CH Hansens Limited. Subsequently, the yoghurt was
fortified with a novel purple tea puree at the Food and Tea Science Workshop of
Karatina University, Kenya. Proximate composition and physiochemical properties
(pH and mineral salts profile) were analyzed both in the formulated probiotic yoghurt
(PYFPT) and control yoghurt without the tea puree. The viability of the probiotic
colony forming microbes was determined using the De Man, Rogosa and Sharpe
(MRS) anaerobic bacteria selective culturing agar media. The pH results of PYFPT
(4.24 ± 0.04) was not significantly different (p< 0.05) to that of the control yoghurt
even after 28 days of refrigerated storage. However, proximate composition
recorded significant differences except for the crude fiber content (0.01 ± 0.01 %).
A higher percent moisture content and crude lipid was recorded in the control yoghurt
(88.18±0.01 and (2.11 ± 0.02) than the PYFPT (78.14±0.04 and 1.33 ± 0.09).
Inversely, higher percentage of crude protein, carbohydrates and crude mineral salts
were recorded in the formulated PYFPT (7.96±0.27, 11.17±0.25; 0.81±) than control
yoghurt (4.23±0.01, 5.44±0.04, 0.59±0.01). A profile of ash content of the added
purple tea puree recorded 16 different mineral salts. The macro minerals were the
major, with potassium recording the highest content (282 ppm), followed by sodium
(121 ppm), magnesium (97.2 ppm) and calcium (96.4 ppm). The microbial anaerobic
probiotic count (6.14 - 6.80 log CFU/ml) was not statistically and significantly different
between the PYFPT and the control yoghurt after 28 days of refrigerated storage. In
conclusion, the study demonstrated that it is feasible to formulate nutritious probiotic
yoghurt fortified using purple-leaf tea puree with potential for commercialization.
Description
Article
Keywords
Citation
Muchiri, M. PHYSIOCHEMICAL, PROXIMATE COMPOSITION AND MICROBIAL QUALITY OF A NOVEL PROBIOTIC YOGHURT FORTIFIED WITH PURPLE-LEAF TEA (Camelias sinensis) Mucheru P1, Chege P1 and M Muchiri2.