Chrysophyllum albidum Linn (African star apple) is a fruit with extensive nutritional and medicinal benefits. The fruit and kernel in the seed are both edible. Strains of lactic acid bacteria (LAB) were isolated from fermented seeds and assessed for probiotic characteristics. The extracts in both the unfermented and the fermented aqueous extracts from the kernels obtained from the seeds of C. albidum were subjected to analysis using the gas chromatography/mass spectrometry (GC-MS) method. This analysis identified the bioactive compounds present as possible substrate(s) for the associated organisms inducing the fermentation and the resultant biotransformed products formed. Three potential probiotic LAB strains identified as Lactococcus raffinolactis (ProbtA1), Lactococcus lactis (ProbtA2a), and Pediococcus pentosaceus (ProbtA2b) were isolated from the fermented C. albidum seeds. All strains were non hemolytic, which indicated their safety, Probt (A1, A2a, and A2b) grew in an acidic environment (pH 3.5) during the 48-h incubation time, and all three strains grew in 1% bile, and exhibited good hydrophobicity and auto-aggregation properties. Mucin binding proteins was not detected in any strain, and bile salt hydrolase was detected in all the strains. l-lactic acid (28.57%), norharman (5.07%), formyl 7E-hexadecenoate (1.73%), and indole (1.51%) were the four major constituents of the fermented kernel of the C. albidum, while 2,5-dimethylpyrazine (C1, 1.27%), 3,5-dihydroxy-6-methyl-2,3-dihydropyran-4-one (C2, 2.90%), indole (C3, 1.31%), norharman (C4, 3.01%), and methyl petroselinate (C5, 4.33%) were the five major constituents of the unfermented kernels. The isolated LAB are safe for consumption. The fermenting process metabolized C1, C2, and C5, which are possible starter cultures for the growth of probiotics. Fermentation is an essential tool for bioengineering molecules in foods into safe and health beneficial products.

Solenostemon monostachyus is an underutilized plant that is yet to be explored for consumption. This study assessed the biochemical impacts of a probiotic Enterococcus faecalis as an agent of fermentation, promoting the edible properties of the leaves from S. monostachyus using either an unfermented water leaf or S. monostachyus. The results with p < 0.05 were considered statistically significant. The α-amylase activity, proteins, carbohydrates, and ash, iron, and copper contents significantly increased (p < 0.05), while fats, crude fiber, cadmium, and manganese contents of the fermented S. monostachyus leaves were significantly reduced (p < 0.05), compared to the control (unfermented water leaves). The total phenol and saponin contents of the leaves were 1.98 ± 0.03 and 2.77 ± 0.04 mg GAE/mL for the S. monostachyus, 2.20 ± 0.01 and 2.39 ± 0.51 mgGAE/mL for water leaf, respectively on Day 5. Spirostanol (20.7343 mg/10 g) and two possible yet-to-be-identified saponin compounds P-S1 (33.5773 mg/10 g) and P-S2 (23.5718 mg/10 g) were newly synthesized along with one possible novel volatile compound by the fermentation process. Furostanol (19.873–29.420), gallic acid (88.111–98.949 mg/10 g), luteolin (0.954–11.712 mg/10 g) were retained, and aescin (69.510 mg/10 g) was completely consumed by the fermentation process. E. faecalis derived some micronutrients to drive the α-amylase catalyzed biotransformation of phytochemicals to improve the health benefits in the leafy vegetable.

Terminalia catappa L. (tropical almond) is a nutritious fruit found mainly in the tropics. This study is aimed to establish the naturally biotransformed molecules and identify the probiotic agents facilitating the fermentation. The aqueous extracts from both the unfermented and fermented T. catappa nuts were subjected to gas chromatography/mass spectrometry (GC/MS) analysis. Syringol (6.03%), glutamine (1.71%), methyl laurate (1.79%), methyl palmitate (1.53%), palmitic acid (5.20%), palmitoleic acid (2.80%), and methyl oleate (2.97%) were detected in the unfermented nuts of the T. catappa. Additionally, two of these natural compounds (palmitic acid (4.19%) and palmitoleic acid (1.48%)) survived the fermentation process to emerge in the fermented seeds. The other natural compounds were biotransformed into 2,3-butanediol (1.81%), butyric acid (16.20%), propane-1,3-diol (19.66%), neoheptanol (2.89%), 2-piperidinone (6.63%), palmitoleic acid (1.18%), formamide, n-(p-hydroxyphenethyl)- (2.80%), and cis-vaccenic acid (1.69%) that newly emerged in the fermented seeds. The phytochemical compounds are likely carbon sources for the organisms facilitating the biotransformed molecules and product production. Four (4) potential probiotic bacteria strains, namely, Probt B1a, Probt B2a, Probt B4a, and Probt B4b, were isolated from the fermented nut. Enterococcus faecum, and Enterococcus faecalis were the organisms identified as driving the fermentation of the seeds. All strains were gram-positive, catalase-negative, and non-hemolytic, which suggests their harmless nature. N-(p-hydroxyphenethyl)-) was associated with fermentation for the first time, and neoheptanol was discovered as the main alcoholic molecule formed during the fermentation of the seeds. This fermentation is a handy tool for bio-transforming compounds in raw food sources into compounds with nutritious and therapeutic potentials.

Cyathea dregei (CD) is a weed plant that is rarely consumed. This study investigated the impact of Enterococcus faecalis as an agent of 3–5-day fermentation, thus stimulating the edible properties of the leaves from CD using Talinum fruticosum as the control. The proximate content, biochemical, antioxidant properties, and phytochemical constituents of the unfermented and fermented leaves were examined. The lactate dehydrogenase activity (LDH) activity significantly increased (p < 0.05) due to the fermentation, which peaked on the third day. The fat, ash, and crude fiber constituents of the fermented CD leaves were significantly higher (p < 0.05), especially on day 3, compared to the unfermented leaves of CD. The leaves of CD naturally possess significantly higher (p < 0.05) values of calcium, selenium, magnesium potassium, sodium, zinc, and vitamin C but significantly lower (p < 0.05) values of vitamins A and E compared to those of water leaf. The fermentation aided the synthesis of caffeic acid (61.71 mg/10 g extract), eleven other bioactive phytochemicals (0.14–60.24 mg/10 g extract), two unexplored saponins (P-Scd, 52.05 mg/10 g extract), and a phenolic compound (P-Pcd, 0.23 mg/10 g extract). Four novel intermediary compounds and six other established compounds were freshly identified with fermentation. The leaves of C. dregei are naturally rich in bioactive nutrients and phytochemicals that trigger their strong antioxidant qualities, which were improved by this fermentation technique. E. faecalis is most likely to engage LDH in driving the fermentation transforming the C. dregei into a potential edible vegetable.

Chrysophyllum albidum is a crop of commercial value in Nigeria, however, the seeds are either used for local games or thrown away. This study aimed at exploring this under-utilized kernel as a novel source for obtaining health beneficial bacteria with desired probiotic characteristics. Isolation of potential probiotic bacteria from naturally fermented C. albidum seeds was carried out and followed by their safety evaluation, Gram staining, catalase test, acid tolerance, bile tolerance, cellular hydrophobicity and auto-aggregation assays. 16S rRNA sequencing and the detection of bile salt hydrolase (bsh) gene were the molecular methods applied for the bacteria characterization. Three potential probiotic bacteria were isolated from the fermented seeds. All isolates were non-haemolytic, Gram positive cocci, and catalase negative, grew in 1% bile, acidic pH of 3.5, and showed good auto-aggregation property. 16Sr RNA sequencing revealed isolates to be strains of Enterococcus durans, and the bsh gene was detected in all the strains. In conclusion, novel naturally fermented foods as seen in the fermented C. albidum kernels can serve as sources for the isolation of probiotic bacteria with great interest, and thus serve as starter culture to improve the organoleptic property of dairy and non-dairy foods.