Optimization of Aqueous Extraction of Polyphenols from Cuminum cyminum Seeds Using Response Surface Methodology and Assessment of Biological Activity.

(1) Background: Cumin seeds, extracted from the plant Cuminum cyminum, are abundant in phenolic compounds and have been extensively researched for their chemical makeup and biological effects. The objective of this research is to enhance the water extraction of polyphenols through the water bath (WB) technique and to evaluate the antiradical, antibacterial, and anticancer effects of the extract. (2) Methods: Response Surface Methodology was used to find the best parameters to extract polyphenols. Three experimental parameters, time, temperature, and solid-liquid ratio, were tested. The disc diffusion method has been used to determine the antimicrobial activities against Salmonella Typhimurium, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, and Candida albicans. The antiradical activity was performed using the DPPH method, while total phenolic content was performed using Folin-Ciocalteu. High-Performance Liquid Chromatography (HPLC) was conducted to analyze the phytochemical profile of WB extracts. The anticancer activity of the lyophilized extract was assessed against three cancer cell lines (colon (HT29), lung (A549), and breast (MCF7) cancer cell lines).; (3) Results: The optimal conditions for water extraction were 130 min at 72 °C. The total phenolic compounds yield (14.7 mg GAE/g DM) and antioxidant activity (0.52 mg trolox eq./mL) were obtained using a 1:40 solid-liquid ratio. The primary polyphenols identified were the flavonoids rutin (0.1 ppm) and ellagic acid (3.78 ppm). The extract had no antibacterial or antifungal activities against the microorganisms tested. The extract showed anticancer activity of about 98% against MCF7 (breast cancer cell line), about 81% against HT29 (colon cancer cell line), and 85% against A549 (lung cancer cell line) at high doses. (4) Conclusions: Extraction time and a high solid-liquid ratio had a positive impact on polyphenol recovery and in maintaining their quantity and quality. Furthermore, the optimal aqueous extract exhibited strong antiradical activity reflected by the inhibition of free radicals in addition to a significant specificity against the tested cancer cell lines.

Purification of Natural Pigments Violacein and Deoxyviolacein Produced by Fermentation Using Yarrowia lipolytica.

Violacein and deoxyviolacein are bis-indole pigments synthesized by a number of microorganisms. The present study describes the biosynthesis of a mixture of violacein and deoxyviolacein using a genetically modified Y. lipolytica strain as a production chassis, the subsequent extraction of the intracellular pigments, and ultimately their purification using column chromatography. The results show that the optimal separation between the pigments occurs using an ethyl acetate/cyclohexane mixture with different ratios, first 65:35 until both pigments were clearly visible and distinguishable, then 40:60 to create a noticeable separation between them and recover the deoxyviolacein, and finally 80:20, which allows the recovery of the violacein. The purified pigments were then analyzed by thin-layer chromatography and nuclear magnetic resonance.

Peanut Allergenicity: An Insight into Its Mitigation Using Thermomechanical Processing.

Peanuts are the seeds of a legume crop grown for nuts and oil production. Peanut allergy has gained significant attention as a public health issue due to its increasing prevalence, high rate of sensitization, severity of the corresponding allergic symptoms, cross-reactivity with other food allergens, and lifelong persistence. Given the importance of peanuts in several sectors, and taking into consideration the criticality of their high allergic potential, strategies aiming at mitigating their allergenicity are urgently needed. In this regard, most of the processing methods used to treat peanuts are categorized as either thermal or thermomechanical techniques. The purpose of this review is to provide the reader with an updated outlook of the peanut's allergens, their mechanisms of action, the processing methods as applied to whole peanuts, as well as a critical insight on their impact on the allergenicity. The methods discussed include boiling, roasting/baking, microwaving, ultrasonication, frying, and high-pressure steaming/autoclaving. Their effectiveness in alleviating the allergenicity, and their capacity in preserving the structural integrity of the treated peanuts, were thoroughly explored. Research data on this matter may open further perspectives for future relevant investigation ultimately aiming at producing hypoallergenic peanuts.

Phenolic Compounds Recovery from Blood Orange Peels Using a Novel Green Infrared Technology Ired-Irrad®, and Their Effect on the Inhibition of Aspergillus flavus Proliferation and Aflatoxin B1 Production.

The intensification of total phenolic compound (TPC) extraction from blood orange peels was optimized using a novel green infrared-assisted extraction technique (IRAE, Ired-Irrad®) and compared to the conventional extraction using a water bath (WB). Response surface methodology (RSM) allowed for the optimization of ethanol concentration (E), time (t), and temperature (T) in terms of extracted TPC and their antiradical activity, for both WB extraction and IRAE. Using WB extraction, the multiple response optimums as obtained after 4 h at 73 °C and using 79% ethanol/water were 1.67 g GAE/100 g for TPC and 59% as DPPH inhibition percentage. IRAE increased the extraction of TPC by 18% using 52% ethanol/water after less than 1 h at 79 °C. This novel technology has the advantage of being easily scalable for industrial usage. HPLC analysis showed that IRAE enhanced the recovery of gallic acid, resveratrol, quercetin, caffeic acid, and hesperidin. IR extracts exhibited high bioactivity by inhibiting the production of Aflatoxin B1 by 98.9%.

Sprouts Use as Functional Foods. Optimization of Germination of Wheat (Triticum aestivum L.), Alfalfa (Medicago sativa L.), and Radish (Raphanus sativus L.) Seeds Based on Their Nutritional Content Evolution.

Wheat, alfalfa, and radish sprouts are well-renowned for their high nutritional content. However, their optimal imbibition and germination durations are rarely considered in the literature. In this study, reduced imbibition times of 3 h, 10 h, and 4 h were demonstrated for the wheat, alfalfa, and radish seeds, respectively. The evolution of their crude fat, proteins, polyphenols, antioxidant activity, and vitamins were investigated over 7 days of germination. The crude fat and protein loads of these sprouts slightly varied during germination, whereas the phenolic compounds and antioxidant activity maxed out at day 7, 5, and 6 for the wheat, alfalfa, and radish sprouts, respectively, with significant levels of catechin. The vitamins highly increased, showing noteworthy yet different peaks of growth depending on the seed and the vitamin analyzed. Interestingly, alfalfa and radish sprouts, taken at their optimal germination day, would decidedly contribute to meet our Recommended Daily Allowances (RDAs) of vitamins E, A, and B6. Overall, for a greater nutritional content and a potential use of these sprouts as nutraceutical ingredients, our results suggested to leave the wheat, alfalfa, and radish seeds to germinate only over 7, 4, and 6 days, respectively, after which their nutritional quality tended to decrease.

Bioproduction of 2-Phenylethanol through Yeast Fermentation on Synthetic Media and on Agro-Industrial Waste and By-Products: A Review.

Due to its pleasant rosy scent, the aromatic alcohol 2-phenylethanol (2-PE) has a huge market demand. Since this valuable compound is used in food, cosmetics and pharmaceuticals, consumers and safety regulations tend to prefer natural methods for its production rather than the synthetic ones. Natural 2-PE can be either produced through the extraction of essential oils from various flowers, including roses, hyacinths and jasmine, or through biotechnological routes. In fact, the rarity of natural 2-PE in flowers has led to the inability to satisfy the large market demand and to a high selling price. Hence, there is a need to develop a more efficient, economic, and environmentally friendly biotechnological approach as an alternative to the conventional industrial one. The most promising method is through microbial fermentation, particularly using yeasts. Numerous yeasts have the ability to produce 2-PE using l-Phe as precursor. Some agro-industrial waste and by-products have the particularity of a high nutritional value, making them suitable media for microbial growth, including the production of 2-PE through yeast fermentation. This review summarizes the biotechnological production of 2-PE through the fermentation of different yeasts on synthetic media and on various agro-industrial waste and by-products.

Single, Subsequent, or Simultaneous Treatments to Mitigate Mycotoxins in Solid Foods and Feeds: A Critical Review.

Mycotoxins in solid foods and feeds jeopardize the public health of humans and animals and cause food security issues. The inefficacy of most preventive measures to control the production of fungi in foods and feeds during the pre-harvest and post-harvest stages incited interest in the mitigation of these mycotoxins that can be conducted by the application of various chemical, physical, and/or biological treatments. These treatments are implemented separately or through a combination of two or more treatments simultaneously or subsequently. The reduction rates of the methods differ greatly, as do their effect on the organoleptic attributes, nutritional quality, and the environment. This critical review aims at summarizing the latest studies related to the mitigation of mycotoxins in solid foods and feeds. It discusses and evaluates the single and combined mycotoxin reduction treatments, compares their efficiency, elaborates on their advantages and disadvantages, and sheds light on the treated foods or feeds, as well as on their environmental impact.

Recent insights in the impact of emerging technologies on lactic acid bacteria: A review.

Lactic acid bacteria (LAB) have a long history of applications in the food industry for fermentation and preservation. This feature is due to their metabolic products that can improve the nutritional and sensory characteristics of foods as well as their antimicrobial compounds that contribute to extend the shelf life of food products. Some emerging technologies including pulsed electric fields (PEF), power ultrasound (US), high-pressure processing (HPP), ultraviolet (UV), and microwave (MW) have attracted great attention for their implementation in the food industry as mild processing technologies. They have the advantage of efficiently inactivating the microorganisms, along with maintaining the fresh attributes of the food products. When applied at a sub-lethal level, these technologies present the potential to enhance several processes, such as improved microbial growth and fermentation conditions, as well as modified metabolic properties of LAB. This review covers the characteristics of LAB and their applications in the food industry. It discusses the impacts of emerging technologies on these microorganisms, with a special focus on microbial inactivation, growth stimulation, and improvement of the beneficial features of LAB by emerging technologies.

Impact of the Physicochemical Composition and Microbial Diversity in Apple Juice Fermentation Process: A Review.

Fermented apple beverages are produced all over the world with diverse characteristics associated with each country. Despite the diversifications, cider producers are confronted with similar issues and risks. The nature of the raw material, also known as the fermentation medium, plays a key role in fermentation. A well-defined composition of apples is, therefore, required to produce cider with good quality. In addition, ferment and its metabolism are important factors in the fermentation process. The producers of cider and other alcoholic beverages are looking in general for novel yeast strains or for the use of native strains to produce "authentic" and diversified beverages that are distinct from each other, and that attract more and more consumers. Research articles on cider production are infrequent compared to wine production, especially on the impact of the chemical composition and microbial diversity of apples on fermentation. Even though the processing of fermented beverages is close in terms of microbial interactions and production, the study of the specific properties of apples and the production challenges of cider production is advantageous and meaningful for cider producers. This review summarizes the current knowledge on apple composition and the impact of the must composition on fermentation and yeast growth. In addition, the microbial diversity of cider, activities, and its influence on fermentation are reviewed.

Effect of Pulsed Electric Fields on the Growth and Acidification Kinetics of Lactobacillus delbrueckii Subsp. bulgaricus.

The aim of this work was to investigate the effect of pulsed electric fields (PEF) on the growth and acidification kinetics of Lactobacillus delbrueckii subsp. bulgaricus CFL1 during fermentation. The PEF treatments were applied during the fermentation process using a recirculation pump and a PEF treatment chamber coupled with a PEF generator. The medium flow rate through the chamber was first optimized to obtain the same growth and acidification kinetics than the control fermentation without medium recirculation. Different PEF intensities (60-428 V cm-1) were then applied to the culture medium to study the impact of PEF on the cells' behavior. The growth and acidification kinetics were recorded during the fermentation and the specific growth rates µ, pH, and acidification rate (dpH/dt) were assessed. The results obtained showed a biphasic growth by applying high PEF intensities (beyond 285 V cm-1) with the presence of two maximal specific growth rates and a decrease in the acidification activities. It was demonstrated that the cells were stressed during the PEF treatment, but presented an accelerated growth after stopping it, leading thereby to similar absorbance and pH at the end of the fermentation. These results show the great potential of PEF technology to be applied to generate low acidified products by performing PEF-assisted fermentations.

Evaluation of the fermentative capacity of an indigenous Hanseniaspora sp. strain isolated from Lebanese apples for cider production.

The present work studied the fermentative potential and carbon metabolism of an indigenous yeast isolated from Lebanese apples for cider production. The indigenous yeast strain was isolated from a spontaneous fermented juice of the Lebanese apple variety 'Ace spur'. The sequencing of the Internal Transcribed Spacer (ITS) domain of rRNA identified the isolated yeast strain as a member of the Hanseniaspora genus. These results suggest an intragenomic ITS sequence heterogeneity in the isolated yeast strain specifically in its ITS1 domain. The different investigations on the yeast carbon metabolism revealed that the isolated yeast is 'Crabtree positive' and can produce and accumulate ethanol from the first hours of fermentation. Thus, our findings highlight the possibility of using the isolated indigenous Hanseniaspora strain as a sole fermentative agent during cider production.

Date Seeds as a Natural Source of Dietary Fibers to Improve Texture and Sensory Properties of Wheat Bread.

The aim of this work was to investigate the effect of date seed water-soluble polysaccharides (DSP) and hemicellulose (DSH) as dietary fiber sources in enhancing the wheat bread's quality. DSP and DSH were extracted from the three date seed varieties Deglet Nour, Ghars Souf, and Allig. The extraction yields ranged from 3.8% to 6.14% and from 13.29% to 18.8%, for DSP and DSH, respectively. DSP and DSH showed interesting functional properties and were incorporated at 0.5% and 0.75% (w/w) in wheat flour with low bread-making quality (FLBM). The results showed that the addition of 0.75% DSH significantly improved the alveograph profile of the dough, and in a more efficient way than that of DSP. Furthermore, bread evaluation revealed that the addition of DSH considerably improved the volume (by 24.22%) and the texture profile of bread (decrease of the hardness and chewiness by 41.54% and 33.81%, respectively), compared to control bread (prepared with FLBM). A sensory analysis showed that the better overall acceptability was found for bread supplemented with DSH. Results in this work demonstrate that hemicellulose fraction extracted from date seeds (DSH) and added with a level of 0.75% to FLBM represents the component that improved bread quality the best.

Water-Soluble Polysaccharides from Ephedra alata Stems: Structural Characterization, Functional Properties, and Antioxidant Activity.

In this study, the physicochemical characterization, functional properties, and antioxidant activity of polysaccharides extracted from Ephedra alata (EAP) were investigated. EAP were extracted in water during 3 h with a liquid/solid ratio of 5 in a water bath at 90 °C. The structure of the extracted EAP was examined by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and gas chromatography-mass spectrometry (GC-MS). The functional properties and biochemical activities of EAP were determined. The chemical analysis revealed that the contents of carbohydrates, uronic acid, and proteins were 73.24% ± 1.24%, 6.82% ± 0.57%, and 6.56% ± 0.36%, respectively. The results showed that the extracted EAP essentially contain three functional groups: C=O, C-H, and O-H. SEM images showed that EAP present numerous high porosity particles. The monosaccharide composition revealed a polymer composed of glucose (43.1%), galactose (36.4%), mannose (14.9%), arabinose (3.7%), and gluconic acid (1.7%). EAP showed interesting functional properties (solubility, oil holding capacity, foaming and emulsion properties). Finally, the results revealed that EAP displayed excellent antihypertensive and antioxidant activities. Overall, EAP present a promising natural source of food additives, antioxidants, and antihypertensive agents.

Pulsed electric field-assisted fermentation of Hanseniaspora sp. yeast isolated from Lebanese apples.

Hanseniaspora sp. yeast was stimulated using pulsed electric field (PEF) during the different fermentation phases. The impact of PEF parameters on the growth rate and substrate consumption was studied. The PEF intensities chosen for this study were mainly in the range of 72-285 V cm-1. A PEF treatment chamber was designed for this study with a ratio of 1:50 between the volume of the fermenter and the volume of the chamber. It allows the recycling of the culture medium using a peristaltic pump, and the yeast treatment by PEF during the fermentation. The continuous circulation of the medium allows avoiding the increase of the temperature inside the fermenter, the cell aggregation, as well as the agitation and the scale-up issues that are associated with the PEF treatment of the entire volume in batch mode. The maximal yeast growth rate was obtained using an electric field strength of 285 V cm-1 applied during both Lag and early exponential phase, and Log phase. This observation was accompanied by a faster consumption of glucose in the medium during the fermentation. Besides, the sensitivity of Hanseniaspora sp. yeast to PEF treatment was more pronounced during the Lag and early exponential phase than the Log phase. The results obtained exposed the great benefit of stimulating Hanseniaspora sp. yeast using moderate PEF as it reduces the fermentation time along with increasing the biomass concentration.

Ultrasound-assisted fermentation for cider production from Lebanese apples.

The present work studies the impact of low-intensity ultrasound (US) on Hanseniaspora sp. yeast fermentations. The effect of pulse duration and growth phase on US application was first evaluated using a synthetic medium. The optimal conditions were then applied to apple juice US-assisted fermentation. An US treatment chamber was first designed to allow the recycling of the culture medium. The optimal US pulse duration on the yeast growth rate was of 0.5 s followed by 6 s rest period, and during 6 h of both Lag and Log phases. These US parameters led to a faster consumption of glucose in the medium during the fermentation, compared to the untreated culture. The impact of US was also depending on the growth phase, showing higher sensitivity of the yeast to US during the Lag phase rather than the Log phase. US-assisted fermentation of apple juice showed a significant increase in biomass growth and glucose consumption, along with a significant decrease in the ethanol yield. The fastest growth kinetic (by 52%), and the highest ethanol reduction (by 0.55% (v, v)) were obtained for the treatment during the first 12 h of fermentation, thereby, the stationary phase was reached faster, and the maximum biomass growth rate was 10 folds higher compared to the untreated culture. The results obtained in this study demonstrated the promising efficiency of US-assisted fermentation in stimulating the biomass growth and reducing the ethanol content in alcoholic beverages.

A Combined Metabolomics and Fluxomics Analysis Identifies Steps Limiting Oil Synthesis in Maize Embryos.

Enhancing fatty acid synthesis (FAS) in maize (Zea mays) has tremendous potential nutritional and economic benefits due to the rapidly growing demand for vegetable oil. In maize kernels, the endosperm and the embryo are the main sites for synthesis and accumulation of starch and oil, respectively. So far, breeding efforts to achieve elevated oil content in maize have resulted in smaller endosperms and therefore lower yield. Directly changing their carbon metabolism may be the key to increasing oil content in maize kernels without affecting yield. To test this hypothesis, the intracellular metabolite levels were compared in maize embryos from two different maize lines, ALEXHO S K SYNTHETIC (Alex) and LH59, which accumulate 48% and 34% of oil, respectively. Comparative metabolomics highlighted the metabolites and pathways that were active in the embryos and important for oil production. The contribution of each pathway to FAS in terms of carbon, reductant, and energy provision was assessed by measuring the carbon flow through the metabolic network (13C-metabolic flux analysis) in developing Alex embryos to build a map of carbon flow through the central metabolism. This approach combined mathematical modeling with biochemical quantification to identify metabolic bottlenecks in FAS in maize embryos. This study describes a combination of innovative tools that will pave the way for controlling seed composition in important food crops.

Effect of high hydrostatic pressure on background microflora and furan formation in fruit purée based baby foods.

The baby foods industry is currently seeking technologies to pasteurize products without formation of processing contaminants such as furan. This work demonstrates the applicability of high hydrostatic pressure (HHP) as a non-thermal decontamination intervention for fruit purée based baby foods. HHP processing was evaluated at 200, 300, and 400 MPa pressures, for 5, 10 and 15 min of treatment times at 25, 35 and 45 °C. HHP application at 400 MPa, 45 °C for 15 min ensured complete inactivation (about 6 log10) of total mesophilic aerophiles, as well as yeasts and molds. No furan was detected in HHP processed products. Thus, the key advantage of HHP over thermal processing is the ability to achieve commercially acceptable microbiological inactivation while avoiding the formation of processing contaminants such as furan.