Findings pointed to a higher antioxidant capacity compared to the loaf breads infused with ascorbic acid and potassium sorbate.
The researchers believe these extracts “might represent alternatives to commercial additives depending on the intended preservative effect”.
Additives such as ascorbic acid (an antioxidant) and potassium sorbate (a preservative), are commonly used in food processing to ensure the desired texture and flavour is acheived to ensure product quality.
Their use is restricted in terms of amounts in food products by the European Food Safety Authority (EFSA), who have deemed the additives as toxic in high amounts.
Natural extracts not only appear to be viable alternatives but also satisfy consumers, who increasingly care about health and well-being and as such, prefer food labelled as healthier and more natural.
As well as additives, antimicrobials, antioxidants and antibrowning agents are among the additives mostly used by the food industry to preserve products for longer periods.
Researchers from the Polytechnic Institute of Bragança in Portugal and the University of Belgrade in Serbia established three study groups: control (without addition of any additive), bread incorporated with ascorbic acid (E300) and bread incorporated with potassium sorbate (E202).
For each group, the team performed a series of analytical tests three times throughout the study period: immediately after infusion and after three and seven days.
Additional loaf bread samples infused with catechin, from strawberry tree fruits, and rosmarinic acid from basil leaves, were also included in the experiment.
The research team found both natural extracts presented antioxidant activity, without toxicity up to the maximal tested dose (400 micrograms per millilitre (μg/mL))
Additionally, the breads incorporated with the natural extracts, especially basil, presented a higher antioxidant capacity than the loaf breads incorporated with ascorbic acid and potassium sorbate.
“Strawberry tree fruits and basil leaves ethanolic extracts showed strong bioactivities,” the study said.
“The protective effects have been attributed to the presence of phenolic compounds; in particular, catechins that have attracted attention, particularly due to their relative high antioxidant activity.”
“Rosmarinic acid has been characterized as one of the most abundant caffeic acid esters present in Ocinium spp (basil).”
Basil’s preservative qualities
Basil’s ability to preserve food products whilst maintaining nutritional properties has been shown in a previous study designed to show the extract’s effectiveness in increasing shelf life and potential health effects.
The extract’s essential oils have also been added to fish gelatine films to maintain the quality of the fish whilst the seed gum of basil has also been incorporated in ice cream and cheese, to maintain their rheological, physical and sensory properties.
Source: LWT - Food Science and Technology
Published online ahead of print: doi.org/10.1016/j.lwt.2017.09.041
“Arbutus unedo L. and Ocimum basilicum L. as sources of natural preservatives for food industry: A case study using loaf bread.”
Authors: Sallawi Takwa et al.