Characterization of Portulaca oleracea Whole Plant: Evaluating Antioxidant, Anticancer, Antibacterial, and Antiviral Activities and Application as Quality Enhancer in Yogurt

Purslane (Portulaca oleracea L.) is rich in phenolic compounds, protein, and iron. This study aims to produce functional yogurt with enhanced antioxidant, anticancer, antiviral, and antimicrobial properties by including safe purslane extract in yogurt formulation; the yogurt was preserved for 30 days at 4 °C, and then biochemical fluctuations were monitored. The purslane extract (PuE) had high phenolic compounds and flavonoids of 250 and 56 mg/mL, respectively. Therefore, PuE had considerable antioxidant activity, which scavenged 93% of DPPH˙, inhibited the viability of MCF-7, HCT, and HeLa cell lines by 84, 82, and 80%, respectively, and inhibited 82% of the interaction between the binding between Spike and ACE2 compared to a SARS-CoV-2 inhibitor test kit. PuE (20-40 µg/mL) inhibited the growth of tested pathogenic bacteria and Candida strains, these strains isolated from spoild yogurt and identified at gene level by PCR. Caffeic acid glucoside and catechin were the main phenolic compounds in the HPLC profile, while the main flavor compound was carvone and limonene, representing 71% of total volatile compounds (VOCs). PuE was added to rats' diets at three levels (50, 150, and 250 µg/g) compared to butylated hydroxyanisole (BHA). The body weight of the rats fed the PuE diet (250 µg/g) increased 13% more than the control. Dietary PuE in rats' diets lowered the levels of low-density lipoprotein (LDL) levels by 72% and increased the levels of high-density lipoprotein (HDL) by 36%. Additionally, liver parameters in rats fed PuE (150 µg/g) decreased aspartate aminotransferase (AST), alanine aminotransferase (ALT), and malondialdehyde (MDA) levels by 50, 43, and 25%, respectively, while TP, TA, and GSH were increased by 20, 50, and 40%, respectively, compared to BHA. Additionally, PuE acts as a kidney protector by lowering creatinine and urea. PuE was added to yogurt at three concentrations (50, 150, and 250 µg/g) and preserved for 30 days compared to the control. The yogurt's pH reduced during storage while acidity, TSS, and fat content increased. Adding PuE increased the yogurt's water-holding capacity, so syneresis decreased and viscosity increased, which was attributed to enhancing the texture properties (firmness, consistency, and adhesiveness). MDA decreased in PuE yogurt because of the antioxidant properties gained by PuE. Additionally, color parameters L and b were enhanced by PuE additions and sensorial traits, i.e., color, flavor, sugary taste, and texture were enhanced by purslane extract compared to the control yogurt. Concerning the microbial content in the yogurt, the lactic acid bacteria (LAB) count was maintained as a control. Adding PuE at concentrations of 50, 150, and 250 µg/g to the yogurt formulation can enhance the quality of yogurt.

Physicochemical, functional and sensory properties of probiotic yoghurt flavored with white sapote fruit (Casimiroa edulis)

Yoghurt is one of the health-functional foods and its nutritive value can be enhanced by adding native fruit. This study aimed to produce novel functional probiotic yoghurt using Bifidobacterium longum (B. longum) strain and White sapote fruits pulp (WSP) at levels of 5, 10, and 15%. WSP contains 19.87% carbohydrates, 0.90% protein, 0.35% fat, 0.78% fiber, 0.6% ash, 48.70 (mg GAE/100 g) total phenolic, 28.25 (mg/100 g) ascorbic acid and 153.53 (IC50 (mg/mL)) for antioxidant activity. Physicochemical, microbiological and sensory evaluation of flavored yoghurt samples were investigated during storage at 5 ± 1 °C for 21 days. The results revealed that increases in total solids, protein, ash, and carbohydrates content were observed in the flavored probiotic yoghurt compared to the control sample. Syneresis and WHC values of flavored yoghurt were influenced by supplementation with WSP whether in fresh or stored samples. Furthermore, significant (P< 0.05) increases in ascorbic acid, antioxidant activity, total phenols, vitamins, and minerals were observed in flavored probiotic yoghurt. Molds & yeast were not detected in all samples except in both control and probiotic yoghurt samples that appeared after 14 and 21 days. Similarly, coliforms were not found in all fresh and stored yoghurt samples. Sensory evaluation results showed that probiotic yoghurt flavored with 10% WSP had the highest acceptance scores compared to other treatments.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05393-5.

Bioactive peptides supplemented raw buffalo milk: Biological activity, shelf life and quality properties during cold preservation

This study aimed to prolong the raw buffalo milk handling and cold storage period by controlling the microbes, enhancing sensory properties and their functionality after supplementing bioactive peptides. The additions included hen and duck egg white protein isolates (HPI and DPI), pepper seed protein (PSP), and pepsin-kidney bean protein hydrolysate (PKH). Five milk treatments were prepared and evaluated as non-supplemented milk (M- Control), hen egg white protein isolate-supplemented milk (M-HPI), duck egg white protein isolate-supplemented milk (M-DPI), pepper seeds protein-supplemented milk (M-PSP), and kidney bean hydrolysate-supplemented milk (M-PKH). Pyrogallol, protocatechuic, catechin, benzoic and caffeine were the main phenolic compounds, Apignin-6-arabinose, naringin, hesperidin, naringenin, kaempferol 3-2-p-comaroyl were the dominant flavonoids in milk samples based on HPLC profile. During 30 days of cold storage, the antioxidant potential of peptides-supplemented milk samples was significantly decreased (p ≤ 0.05) as decrement of phenolic compounds and flavonoids; the pH was nearly stable, the titratable acidity and total soluble solids (TTS) were (p ≤ 0.05) raised. PSP and PKH were inhibited (p ≤ 0.05) the decay of sugars in M-PSP, and M-PKH by reducing 45% of bacterial load as compared to other milk samples. PSP was significantly (p ≤ 0.05) scavenged 87% of DPPḢ compared to other peptides. Besides, PSP followed by PKH reduced considerably (p ≤ 0.05) the growth of tested bacteria, molds, and yeasts. The PSP has significantly increased the whiteness of M-PSP as compared to other milk samples. M-PSP had the highest score in color, taste, and flavor, followed by M-PKH.