This study investigates the effect of flaxseed oil towards physicochemical and sensory properties of reduced fat ice creams and its stability in ice-creams upon storage. Three formulations, (F1, F2, F3) were developed by substituting milk fat with flaxseed oil at levels of 2.5%, 5.0% and 7.5%, (w/w) respectively. Samples were subjected to sensory evaluation and analyses such as meltdown, titratable acidity, pH, total solids, protein and fatty acids composition. Incorporation of flaxseed oil into ice-cream showed no effects on physicochemical properties of the ice-creams. However, it increased the colour of ice-cream towards yellowness, decreased the sweetness, smoothness and creaminess. Flaxseed oil incorporation also slightly (P < 0.05) decreased the acceptance level of aroma, flavour, texture and overall acceptability of formulated icecreams. The most acceptable level of flaxseed oil substitution is at 2.5 %. Gas chromatography analysis showed that fatty acids slightly decreased upon storage.
The present study was aimed to investigate the efficacy of fenugreek seeds as a potential natural source of antioxidants and antimicrobials. Fenugreek seed (FS) extracts were prepared using ethanol (75%), methanol (75%) and water as extraction solvents. Ethanol (E-FSP), methanol (M-FSP), water (W-FSP) and hot water (HW-FSP) extracts were obtained from ground FS, whilst water extract (W-GeFS) was obtained from germinated FS. The results revealed that all extracts of the ground FS exhibited antioxidant and antimicrobial activities and the extractability of bioactive compounds in the presence of water was higher in germinated seeds (W-GeFS). Highest phenolic (156.3 mg GAE/ g) and flavonoid (38.5 mg CE/ g) contents were found in W-GeFS. It also showed the strongest DPPH radical-scavenging activity of 68 % inhibition at a lower concentration (0.06 mg/ ml). In addition, highest vitamin C equivalent antioxidant capacity (143.28 mg vitamin C/ g) with an IC50 value of 42.1 μg/ ml were found in W-GeFS. Based on disc diffusion method, W-GeFS exhibited highest antimicrobial activity against all tested bacterial pathogens (Bacillus subtilis, Staphylococcus aureus, and Escherichia coli). Thus, it can be concluded from the results that W-GeFS extract from germinating fenugreek seeds (W-GeFS) has the potential to be used as a natural source of bioactive compounds with varied applications in food industry especially, for active film packaging purposes to prolong the shelf-life of food products.
Antibacterial effect of modified sago starch-alginate edible film incorporating lemongrass oil at various concentrations was studied. Edible films were prepared from a mixture of modified sago starch and alginate. Lemongrass oil (0.1 - 0.4%, v/w) and glycerol (0 and 20%, w/w) were incorporated in the films to act as natural antimicrobial agent and plasticizer, respectively. The films were characterized for antibacterial activity against food pathogenic bacteria such as Escherichia coli O157:H7, Salmonella Enteritidis and Staphylococcus aureus. The edible film exhibited antibacterial activity against Escherichia coli O157:H7 and Salmonella Enteritidis by using agar diffusion assay method. For films tested against Escherichia coli O157:H7, the zone of inhibition increased significantly (p < 0.05) with addition of lemongrass oil at all levels both in the presence and absence of glycerol. The films also significantly (p < 0.05) inhibited the growth of Salmonella enteritidis only with 0.4% lemongrass oil (in the presence and absence of glycerol). However, the films containing lemongrass oil did not show any inhibition effect on Staphylococcus aureus.