Prolonged tempe-type fermentation in order to improve bioactive potential and nutritional parameters of quinoa seeds

Agro-morphological and biochemical responses of quinoa (Chenopodium quinoa Willd. var: ICBA-Q5) to organic amendments under various salinity conditions

In the Sahara Desert, due to drought and salinity and poor soil fertility, very limited crop choice is available for the farmers to grow crops. Quinoa (Chenopodium quinoa Willd.) has shown promising under such conditions in the South of Morocco, a true representative site of Sahara Desert. Soil organic amendments have the potential to minimize negative effects of soil salinity and improve crop production. Thus, this study aimed to elucidate the impact of nine organic amendments on quinoa (var. ICBA-Q5) growth, productivity, and biochemical parameters under saline irrigation water application (4, 12, and 20 dS·m^-1). Results of the experiment indicate a significant effect of organic amendments on major agro-morphological and productivity parameters. Biomass and seed yield tends to decrease with the rise of salinity level, and organic amendments have improved productivity compared to the non-treated control. However, salinity stress alleviation was assessed by determining pigments concentration, proline content, phenolic compounds, and antioxidant activity. Therefore, the action of organic amendments varies from one level of salinity to another. Furthermore, a remarkably significant decrease in total saponin content was reached due to the application of amendments even at high saline conditions (20 dS·m^-1). The results demonstrate the possibility of enhancing the productivity of quinoa as an alternative food crop under salinity conditions by using organic amendments and improving the quality of grains (saponin reduction) during the pre-industrialization process.

Identification and Bioaccessibility of Maillard Reaction Products and Phenolic Compounds in Buckwheat Biscuits Formulated from Flour Fermented by Rhizopus oligosporus 2710

The identification and potential bioaccessibility of phenolic compounds using the highly sensitive micro-HPLC-QTRAP/MS/MS technique and Maillard reaction products (MRPs) in buckwheat biscuits formulated from flours, raw and roasted, fermented by Rhizopus oligosporus 2710 was addressed in this study after in vitro digestion. The content of the analyzed MRPs such as furosine, FAST index, and the level of melanoidins defined by the browning index was increased in the biscuits prepared from fermented flours as compared to the control biscuits prepared from non-fermented ones. After in vitro digestion higher content of furosine was observed in control and tested biscuits providing its high potential bioaccessibility. The fermented buckwheat flours used for baking affected the nutritional value of biscuits in comparison to the control biscuits in the context of the twice-increased FAST index. More than three times higher value of the browning index was noted in control and tested biscuits after digestion in vitro indicating the high bioaccessibility of melanoidins. Our results showed the presence of ten phenolic acids and eight flavonoids in the investigated biscuits. Among phenolic acids, vanillic, syringic, and protocatechuic were predominant while in the group of flavonoids, rutin, epicatechin, and vitexin were the main compounds in analyzed biscuits. Generally, the lower potential bioaccessibility of phenolic acids and higher potential bioaccessibility of flavonoids was found for biscuits obtained from buckwheat flours fermented by fungi compared to control biscuits obtained from non-fermented flours. Fermentation of buckwheat flour with the fungus R. oligosporus 2710 seems to be a good way to obtain high-quality biscuits; however, further research on their functional properties is needed.

Production and analysis of metabolites from Solid-State Fermentation of Chenopodium formosanum (Djulis) Sprouts in a Bioreactor

The study utilized fresh fourth-day Chenopodium formosanum sprouts as the substrate for Rhizopus oligosporus fermentation. The resultant products showed higher antioxidant capacity than those from C. formosanum grains. Compared to traditional plate fermentation (PF), fermentation in a bioreactor (BF) (35 °C, 0.4 vvm aeration at 5 rpm) led to higher free peptide content (99.56 ± 7.77 mg casein tryptone/g) and enzyme activity (amylase, glucosidase, and proteinase are 2.21 ± 0.01, 54.57 ± 10.88, and 40.81 ± 6.52 U/g, respectively) than traditional plate fermentation (PF). Using mass spectrometry analysis, two peptides TDEYGGSIENRFMN and DNSMLTFEGAPVQGAAAITEK were predicted to possess high bioactive properties as DPP IV and ACE inhibitors. Additionally, over twenty new metabolites (aromatics, amines, fatty acids, and carboxylic acids) were discovered in the BF system compared to its PF counterpart. Results suggest that using a BF system to ferment C. formosanum sprouts is an appropriate method to scale-up fermentation and enhance nutritional values as well as bioactivities.

Impact of Hydrothermal Treatments on Nutritional Value and Mineral Bioaccessibility of Brussels Sprouts (Brassica oleracea var. gemmifera)

Hydrothermal treatment of Brussels sprouts (Brassica oleracea var. gemmifera) induces both physical and chemical changes in nutrients and non-nutrients. It also affects the bioaccessibility of individual compounds. The aim of this study was to investigate the influence of hydrothermal treatment (boiling, steaming, and sous vide technique) on the concentration of the selected nutrients and non-nutrients in Brussels sprouts and in vitro bioaccessibility of the mineral components. It has been shown that, in terms of the leaching of nutrients and non-nutrients into the aqueous medium, traditional cooking in water involves the greatest percentage loss (the highest decrease in dry matter (11.8%), ash (13.3%), protein (10.4%), crude fat (43.3%), dietary fiber (9.5%), digestible carbohydrates (12.2%), and most of mineral components (7.6–39.8%)). In contrast, steam cooking and sous vide cooking of Brussels sprouts allow a higher level of preservation of the individual compounds. By using reduced process temperatures and vacuum packaging, sous vide cooking can be an alternative to traditional cooking to preserve the higher nutritional value of Brassica oleracea var. gemmifera (preservation of dry matter, ash, crude fat, and most of the mineral components at the level of the raw sample p ≤ 0.05).

Hydrothermal Treatment Effect on Antioxidant Activity and Polyphenols Concentration and Profile of Brussels sprouts (Brassica oleracea var. gemmifera) in an In Vitro Simulated Gastrointestinal Digestion Model

Brussels sprouts are a source of polyphenolic compounds. However, their concentration is affected by many factors depending on the plant material, hydrothermal treatment methods and digestion in the gastrointestinal tract. The aim of this study was to determine the effect of hydrothermal treatment on the antioxidant activity, concentration and profile of polyphenols of Brassica oleracea var. gemmifera in an in vitro simulated gastrointestinal digestion model. The study showed a significant effect of the type of hydrothermal treatment on total polyphenol concentration, polyphenolic acid profile, flavonoid content and antioxidant activity. Traditional boiling in water was the least effective type of hydrothermal treatment with respect to bioactive components of Brussels sprouts. Sous-vide was the most effective hydrothermal treatment in terms of retention of polyphenolic compounds and high antioxidant activity, thus providing a better alternative to steam cooking. Using an in vitro model, a significant difference was demonstrated between the concentration of bioavailable polyphenolic compounds and the polyphenol content of the plant material before digestion. The influence of the type of hydrothermal treatment used on the concentration of bioavailable polyphenolic compounds was maintained in relation to material not subjected to in vitro digestion (except for antioxidant activity).

Impact of solid-state fermentation on factors and mechanisms influencing the bioactive compounds of grains and processing by-products

Cereal and legume grains and their processing by-products are rich sources of bioactives such as phenolics with considerable health potential, but these bioactives suffer from low bioaccessibility and bioavailability, resulting in limited use. Several studies have demonstrated that solid-state fermentation (SSF) with food-grade microorganisms is effective in releasing bound phenolic compounds in cereal and legume products. In this review, we discuss the effect of SSF on cereal and legume grains and their by-products by examining the role of specific microorganisms, their hydrolytic enzymes, fermentability of agri-food substrates, and the potential health benefits of SSF-enhanced bioactive compounds. SSF with fungi (Aspergillus spp. and Rhizopus spp.), bacteria (Bacillus subtilis and lactic acid bacteria (LAB) spp.) and yeast (Saccharomyces cerevisiae) significantly increased the bioactive phenolics and antioxidant capacities in cereal and legume grains and by-products, mainly through carbohydrate-cleaving enzymes. Increased bioactive phenolic and peptide contents of SSF-bioprocessed cereal and legume grains have been implicated for improved antioxidant, anti-inflammatory, anti-carcinogenic, anti-diabetic, and angiotensin-converting-enzyme (ACE) inhibitory effects in fermented agri-food products, but these remain as preliminary results. Future research should focus on the microbial mechanisms, suitability of substrates, and the physiological health benefits of SSF-treated grains and by-products.

Correlations between the Chemical, Microbiological Characteristics and Sensory Profile of Fungal Fermented Food

Fungal fermented foods are nutritious, environmentally friendly and sustainable protein sources. To develop fungal fermented food with acceptable sensory characteristics, it is important to assess factors that can affect the sensory characteristics of the product. The current study aimed to investigate the correlations between the chemical and microbiological characteristics and sensory characteristics of fungal fermented food. Soybeans were fermented using five local Indonesian strains of the genus Rhizopus sp. and one strain of industrial starter to mimic traditional Indonesian tempe. The chemical (amino acid and ammonia content), microbiological (lactic acid bacteria, proteolytic bacteria and yeast) and sensory characteristics of the fermented products were examined. The results showed that there is a correlation between the chemical properties, particularly glutamic acid and aspartic acid, and the overall liking of different types of tempe. In general, Rhizopus oligosporus-fermented products had better sensory characteristics than those fermented with Rhizopus oryzae and Rhizopus delemar. The sensory characteristics of the fermented products in this work made from isolates are comparable to those made with an industrial starter culture. In addition, taste and texture affect the overall liking of the product. The results of this study contribute to the development of acceptable sensory fungal fermented food and, in particular, the screening of potential starters.

In Vitro Expanded Bioaccessibility of Quercetin-3-Rutinoside and Quercetin Aglycone from Buckwheat Biscuits Formulated from Flours Fermented by Lactic Acid Bacteria

The expanded bioaccessibility of rutin (Ru) and quercetin (Q) from buckwheat biscuits (BBs) formulated from liquid-state fermented flours by selected lactic acid bacteria (LAB) were determined after gastrointestinal digestion. Fermentation of buckwheat flours caused a LAB-dependent variation in Ru and Q content. BBs baked at 220 °C for 30 min showed lower content of Ru and Q, and no correlation was found between the content of these compounds in fermented flours and BBs. The expanded bioaccessibility of Ru from BBs was low when its content in the soluble and insoluble fractions remaining after digestion in vitro was taken into account. Contrary results were found for Q bioaccessibility which had an index greater than 1, indicating the high Q bioaccessibility from BBs. Since very low Q content was noted in the insoluble fraction remaining after BBs digestion, the high Q bioaccessibility was determined to be due to its concentration in the soluble fraction.

Protocol for Designing New Functional Food with the Addition of Food Industry By-Products, Using Design Thinking Techniques-A Case Study of a Snack with Antioxidant Properties for Physically Active People

The aim of the work was to develop an easy-to-follow protocol for designing novel functional products with the addition of food industry by-products using design thinking techniques. As a result, a 12-step protocol has been designed and presented. The protocol consists of steps from the initial formation of the design team, through all the stages of the production and prototyping, until establishing the final storage conditions and creating final documentation. The protocol has been validated and explained using a case study in which a fish industry by-product hydrolysate with bioactive properties was used to develop a novel functional food product for physically active people: a date bar with carp meat and carp skin gelatin hydrolysate. Following the 12 steps presented in the protocol resulted in developing a food product with high nutritional value and antioxidant power which remains stable during storage at reduced temperatures. Moreover, the product is characterized by good sensory qualities and can be easily implemented into full-scale production. The newly designed protocol is an easy-to-follow method that could be used in almost any kind of food industry sector to sucesfully develop user-focused functional food products with by-product addition.

Tempeh: A semicentennial review on its health benefits, fermentation, safety, processing, sustainability, and affordability

Tempeh is a fermented food made of mainly soybeans and is a nutritious, affordable, and sustainable functional source of protein. Globally, tempeh is a widely accepted fermented product. Although there is a growing body of literature on tempeh, most research has focused on unfermented soybeans, thus the impact of tempeh fermentation on biological properties of soybeans has been largely left scattered. The objective of this review is to summarize the literature of tempeh fermentation over the past 60 years. A search of articles on tempeh published from 1960 to 2020 was performed using the Cochrane Library, Web of Science, EBSCOhost FSTA database, and Google Scholar. References from identified articles were reviewed for additional sources. In total, 321 papers were selected for this review, of which 64 papers were related to the health benefits of tempeh. This review concluded that sufficient evidence exists in the literature supporting tempeh fermentation as a low-cost, health-promoting, and sustainable food processing technology to produce protein-rich foods using various beans, legumes, and grains. This comprehensive review suggests further studies are needed on tempeh fermentation and its impact on human health; research and standardization of nonsoy tempeh; assessment of food safety-improving modification in tempeh production system; and initiatives supporting the sourcing of local ingredients in tempeh production.

Impact of Fermentation on Phenolic Compounds and Antioxidant Capacity of Quinoa

Quinoa (Chenopodium quinoa Willd.) is increasingly singled out as a healthy food with an excellent nutritional profile. Besides being suitable for gluten-free diets, it is rich in proteins of excellent quality and is a good source of minerals and vitamins, as well as of natural antioxidants, such as phenolic compounds. The aim of this work is to present how fermentation can affect phenolic compound content and antioxidant capacity of quinoa. It emerged that fermentation can be used to increase phenolic compound content and antioxidant capacity in both quinoa seeds and flours. The use of fermented quinoa flours allowed obtaining bread and pasta richer in phenolic compounds and with a greater antioxidant capacity. Fungi are the main starters used in quinoa seed fermentation, while Lactobacillus strains have been applied to produce sourdoughs. Quinoa has been also fermented to obtain yogurt-like beverages with a higher content in phenolic compounds and a greater antioxidant activity. Strains of Lactobacillus sp. and Bifidobacterium sp. have been used as starters.

Fermentation with Edible Rhizopus Strains to Enhance the Bioactive Potential of Hull-Less Pumpkin Oil Cake

Solid-state fermentation with food-grade fungal strains can be applied to enhance the bioactive parameters of agro-industrial by-products. Tempe-type fermentation can be adapted to various substrates, but the key factor is the appropriate strain selection. The aim of this study was to compare the potential of Rhizopus strains for obtaining products of improved antioxidant activity from pumpkin oil cake. For this purpose, substances reacting with the Folin-Ciocalteu reagent, with free radical scavenging potential, as well as reducing power were assessed. The effect of the fermentation on the phytate level and inositol phosphate profile in the material was also monitored. The fermentation resulted in the significant enhancement of the antioxidant potential of pumpkin oil cake in the case of all the strains tested, but the most efficient one was R. oligosporus ATCC 64063. During the course of fermentation, the level of phytate in the material decreased (the highest reduction rate was observed in the oil cake fermented with R. oryzae CBS 372.63), while peptides and fungal glucosamine were accumulated. Tempe-type fermentation can be considered as an alternative way of improving the bioactive parameters of pumpkin oil cake and, thanks to the various activities of different Rhizopus strains, it is possible to obtain products of desired parameters.

The Efficacy of Processing Strategies on the Gastroprotective Potentiality of Chenopodium quinoa Seeds

The current study has been conducted to evaluate the effect of different processing techniques on the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity and the gastroprotective potential of Chenopodium quinoa red seeds in acute gastric injury induced by absolute ethanol in rats. Seven groups of female Sprague Dawley rats were assigned to normal and absolute ethanol (absolute EtOH) groups, given distilled water, reference control omeprazole (OMP, 20 mg/kg), pressure-cooked quinoa seeds (QP, 200 mg/kg), first stage-germinated quinoa seeds (QG, 200 mg/kg), Lactobacillus plantarum bacteria-fermented quinoa seeds (QB, 200 mg/kg), and Rhizopus oligosporus fungus-fermented quinoa seeds (QF, 200 mg/kg). One hour after treatment, all groups were given absolute ethanol, except for the normal control rats. All animals were sacrificed after an additional hour, and the stomach tissues were examined for histopathology of hematoxylin and eosin staining, immunohistochemistry of cyclooxygenase 2 (COX-2), and nitric oxide synthase (iNOS). Stomach homogenates were evaluated for oxidative stress parameters and prostaglandin E₂ (PGE₂). Gene expression was performed for gastric tumor necrosis factor alpha (TNF-α) and nuclear factor kappa of B cells (NF-kB). QB and QG recorded the highest DPPH scavengers compared to QF and QP. The gastroprotective potential of QB was comparable to that of OMP, followed by QF, then QG, and QP as confirmed by the histopathology, immunohistochemistry, and gene expression assessments. In conclusion, differently processed red quinoa seeds revealed variable antioxidant capacity and gastroprotective potential, while the bacterial fermented seeds (QB) showed the highest potential compared to the other processing techniques. These results might offer promising new therapy in the treatment of acute gastric injury.

The Impact of Phytases on the Release of Bioactive Inositols, the Profile of Inositol Phosphates, and the Release of Selected Minerals in the Technology of Buckwheat Beer Production

A relatively high concentration of phytate in buckwheat malt, and the low activity of endogenous buckwheat phytases, both of which limit the effective use of substrates (starch, proteins, minerals) for fermentation and yeast metabolism, gives rise to the potential for application of phytases in beer production. This study aims at obtaining a 100% buckwheat wort with high bioactive cyclitols (myo-inositol and D-chiro-inositol) concentrations released by exogenous phytases and acid phosphatases. Two mashing programs were used in the study, i.e., (1) typical for basic raw materials, namely the well-established Congress method, and (2) optimized for phytase activity. The results indicated a nearly 50% increase in the level of bioactive myo-inositol and an 80% degradation of phytate in the wort as a result of simultaneous application of phytase and phosphatase enzymes in the mashing of buckwheat malt. In addition, high D-chiro-inositol concentrations were released from malt to the buckwheat wort. The concerted action of the two phytases significantly increased (19–44%) Zn²⁺ concentrations in wort. This may be of great importance during mash fermentation by Saccharomyces cerevisiae yeasts. There is a potential to develop technology for buckwheat beer production, which, in addition to being free from gluten, comprises high levels of bioactive myo- and D-chiro-inositols.