Effect of Solid-State Fermentation on Nutritional Quality of Leaf Flour of the Drumstick Tree (Moringa oleifera Lam.)

Solid-state fermentation through synthetic microbiome: An effective strategy for converting Chinese distillers' grains into functional protein feed

Chinese distillers' grains (CDGs), a byproduct of liquor production, have low protein, high fiber, and elevated alcohol/lactic acid levels, limiting their use as animal feed. This study utilised a synthetic microbiome composed of Candida utilis (protein enhancement), Trichoderma viride (fiber reduction), Bacillus subtilis (detoxification), and Lactobacillus casei (functional enhancement) for solid-state fermentation. The results showed that crude protein content increased to 23.61 %, and true protein content to 20.45 %. Crude fiber, ethanol, lactic acid, and acetic acid contents decreased by 22.31 %, 77.25 %, 85.08 %, and 73.89 %, respectively. Amino acid content increased by 23.80 %, and flavour compounds rose by 140.76 %. Mycotoxins like aflatoxin B1 (AFB1) and ochratoxin A (OTA) were undetectable, while vomitoxin (DON) remained below EU limits. In vitro digestibility of dry matter increased by 98.36 %. Pilot-scale trials showed a 1.42-fold increase in crude protein and a 1.34-fold increase in true protein, contributing to more efficient CDG utilisation and reduced agricultural costs.

Immune enhancement and disease resistance against Aeromonas hydrophila infection by dietary Lactobacillus plantarum-fermented Moringa oleifera leaves in Oreochromis niloticus

For enhancing the nutritional characteristics of Moringa oleifera leaves (MOLs), the present research set out to examine the effect of MOLs fermented by Lactobacillus plantarum (MOLF) or MOLs powder (MOLP) on innate immunity defense and resilience to Aeromonas hydrophila challenge in Oreochromis niloticus. A 30-day experiment was conducted with 180 Nile tilapia fingerlings, divided randomly into five equal-sized groups of 36 fingerlings, three replicates per group. The 1st control fish received a basal meal devoid of any supplements. The 2nd MOLP-L and the 3rd MOLP-H fish received basal meals enriched with low and high levels of MOLP (50 g or 100 g/kg diet). The 4th MOLF-L and 5th MOLF-H fish received basal meals enriched with low and high levels of MOLF (50 g or 100 g/kg diet). Ferulic acid, gallic acid, caffeic acid, and p-coumaric acid were the primary phenolic components identified by HPLC in the fermented MOLs. Meanwhile, naringenin, rutin, quercetin, kaempferol, luteolin, apigenin, and catechin were the main flavonoids detected. The results revealed that MOLF dietary supplementation enhanced the immune-related outcomes more significantly (P < 0.05) than MOLP in a dose-related manner. Supplementation of MOLF increased serum nitric oxide and lysozyme levels, phagocytic index, phagocytic %, hepatic superoxide dismutase, and glutathione, yet declined the levels of malondialdehyde more significantly (P < 0.05) than the MOLP. The proinflammatory genes IL1β, TNFα, and IL-2 were significantly (P < 0.0.05) down-regulated. In contrast, the expression of the IL-10 gene was markedly upregulated in the spleen and head kidney (anterior) post A. hydrophila challenge in the MOLF-groups than the MOLP-groups. MOLF-supplemented groups showed a significantly (P < 0.05) enhanced relative proportion of survivorship and survival rates but decreased the A. hydrophila bacterial load (CFU) compared to the MOLP-supplemented groups. In conclusion, our findings have offered new insights into the promising immune-enhancing outcome of MOLF as a dietary supplement for immune augmentation against disease challenges in Nile tilapia.

Effect of Monascus-fermented Moringa oleifera on production performance, carcass characteristics, and meat quality attributes in broilers

This study investigated the production performance, carcass characteristics, and meat quality attributes of broilers fed with different doses of Monascus-fermented Moringa oleifera leaves. A total of 400 one-day-old unsexed Greenleg partridge broilers were randomly divided into 4 dietary which were fed a basal diet supplemented with 0, 5% Monascus-fermented Moringa oleifera leaves, 10% Monascus-fermented Moringa oleifera leaves, and 10% Moringa oleifera leaves, respectively. Each group had 5 replicates of twenty birds each. The whole trial lasted for 63 d. The results indicated that a high dose of Moringa oleifera leaves supplement in broiler diet reduced the production performance, carcass characteristics, and meat quality attributes (P < 0.05). While the addition of the same dose of Monascus-fermented Moringa oleifera leaves reversed this adverse effect, and the 5% Monascus-fermented Moringa oleifer leaves supplement was found to be more effective (P < 0.05). In addition, Monascus-fermented Moringa oleifera leaves improved the concentration of amino acids and polyunsaturated fatty acids in the meat, which could be beneficial for human health. We conclude that, a 5% Monascus-fermented Moringa oleifera leaves supplement in the diet is beneficial in terms of improved growth performance and the functional attributes of meat than sole Moringa oleifera leaves supplement.

Enhancement of nutritional and functional qualities of tropical leaf meal as feed ingredients in chickens through the use of fermentation technology

The poultry industry in developing countries is challenged by the high cost of conventional protein and energy feed ingredients. This problem has burdened researchers to use cheap and readily non-conventional feed ingredients such as tropical leaf meals (TLMs) to reduce the cost of feed. Tropical leaf meals are high in nutrients and important bioactive compounds, such as flavonoids and polyphenols. These important bioactive compounds in TLMs are responsible for their health promoting effects in animals. Research has shown that inclusion of moderate quantities of TLMs in livestock feed improves chicken performance and health. However, the inclusion of high levels of TLMs in poultry diets reduced chicken performance, which may be attributed to low palatability, high fibre content, poor digestibility, and the presence of antinational factors (ANFs) in TLMs. The potential of fermentation to enhance the nutrient content of feedstuffs high in fibre has been reported. Therefore, the objective of this research was to review the current knowledge on the effect of fermentation on nutritional and functional properties of TLMs and their feeding value on broiler chicken and laying hen performance.

Non-targeted metabolomic analysis of non-volatile metabolites in a novel Chinese industrially fermented low-salt kohlrabi

Low-temperature and low-salt fermented Chinese kohlrabi (LSCK) represents a novel approach to producing low-salt kohlrabi without the need for desalination during processing, as compared to traditional techniques. However, the profile of its non-volatile metabolites remains unclear. In order to investigate the non-volatile metabolites and their changes in LSCK during fermentation, the LSCKs fermented for 0 day (0D), 45 days (45D) and 90 days (90D) were analyzed using LC-MS/MS non-targeted metabolomics coupled with multivariate statistical analysis. The results showed that 60, 74, and 68 differential metabolites were identified in the three groups A1 (0D and 45D), A2 (0D and 90D), and A3 (45D and 90D) (VIP >1, p < 0.05, Log2FC >1), respectively. The differential metabolites were mainly amino acids, peptides, and analogues, fatty acyls, organic acids and derivatives, and carbohydrates and carbohydrate conjugates. Seventeen common differential metabolites were identified in A1, A2, and A3 groups. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis suggested that the alanine, aspartate and glutamate metabolism, butanoate metabolism, α-linolenic acid metabolism, arginine biosynthesis, and phenylalanine metabolism were significantly correlated with the differential metabolites. The present study elucidates for the first time the changes in non-volatile differential metabolites and their associated metabolic pathways in the novel Chinese low-salt kohlrabi, providing a theoretical basis for improving the industrial fermentation process of this innovative product.

Bioremediation of Aflatoxin B1 by Meyerozyma guilliermondii AF01 in Peanut Meal via Solid-State Fermentation

The use of microorganisms to manage aflatoxin contamination is a gentle and effective approach. The aim of this study was to test the removal of AFB1 from AFB1-contaminated peanut meal by a strain of Meyerozyma guilliermondii AF01 screened by the authors and to optimize the conditions of the biocontrol. A regression model with the removal ratio of AFB1 as the response value was established by means of single-factor and response surface experiments. It was determined that the optimal conditions for the removal of AFB1 from peanut meal by AF01 were 75 h at 29 °C under the natural pH, with an inoculum of 5.5%; the removal ratio of AFB1 reached 69.31%. The results of simulating solid-state fermentation in production using shallow pans and fermentation bags showed that the removal ratio of AFB1 was 68.85% and 70.31% in the scaled-up experiments, respectively. This indicated that AF01 had strong adaptability to the environment with facultative anaerobic fermentation detoxification ability. The removal ratio of AFB1 showed a positive correlation with the growth of AF01, and there were no significant changes in the appearance and quality of the peanut meal after fermentation. This indicated that AF01 had the potential to be used in practical production.

Determination of performance response of broilers to fermented tropical leaf meal supplementation using meta-analytical method

Fermented tropical leaf meals (FTLM) are currently added to chicken feed to improve chicken productivity due to their reported nutritional and medicinal benefits. However, the effects of FTLM on broiler productivity and health are less clear. Thus, this meta-analysis was designed to assess the effects of FTLM on the performance outcomes of broilers Eleven controlled studies were retrieved and used to explore the impacts of dietary FTLM supplementation on growth performance [feed intake (FI), feed conversion ratio (FCR), average daily gain (ADG)], blood lipids, slaughter performance (abdominal fat, breast and thigh muscles weight), meat quality [pH, drip loss, shear force, lightness (L*), redness (a*), and yellowness (b*)], and intestinal histomorphology [villus height (VH), crypt depth (CD) and VH/CD values] of broilers. Subgroup and meta-regression analyses of the effects of moderators (i.e., leaf meal type, supplementation level, broiler strains, rearing phase, and fermentation microbes) on the growth performance of broilers were also assessed. Results show that dietary FTLM supplementation increased FI [standardised mean difference (SMD) = 0.11; 95% confidence interval (CI): 0.02, 0.20; P < 0.0001], improved ADG (SMD = 0.33; 95% CI: 0.23, 0.43; P < 0.0001) and FCR (SMD =  - 0.21; 95% CI: - 0.30, - 0.11; P < 0.0001) in broilers. In addition, FTLM enhanced slaughter performance, meat quality, and intestinal histomorphology of broilers. Broilers fed 0-5 g/kg feed FTLM had better FI, FCR, and ADG than the controls taking significant heterogeneity into account. Meta-regression revealed that analysed moderators influenced growth performance results and accounted for some of the sources of heterogeneity. It can be concluded that up to 5 g/kg of FTLM can be added to broiler feed to improve growth performance, intestinal histomorphology, slaughter performance, and meat quality without adverse effects on dressing percentage and blood lipid profiles.

Effects of Solid-State Fermentation on the Standardized Ileal Digestibility of Amino Acids and Apparent Metabolizable Energy in Peanut Meal Fed to Broiler Chickens

Peanut meal (PNM) is a byproduct of the peanut oil extraction process, but its application is seriously limited by the presence of anti-nutritional factors, imbalance in amino acid profiles, and susceptibility to mycotoxin contamination. This study was conducted to investigate the effects of solid-state fermentation on the nutritional quality of PNM, as well as the effects of PNM and fermented peanut meal (FPNM) on the ileal digestibility of amino acids and apparent metabolizable energy (AME) of broiler chickens. The results indicated that the fermentation improved the quality of PNM by increasing the crude protein, TCA-soluble protein, and L-lactic acid concentration (p < 0.05), and decreasing the crude fiber, phytic acid, and aflatoxin B1 concentration (p < 0.05). Solid-state fermentation also increased the free amino acids level and improved the balance of hydrolyzed amino acids of PNM. A nitrogen-free diet was used to determine the loss of endogenous amino acid in birds, and the PNM or FPNM as the only protein source to formulate semi-purified diets. The result showed that feeding on FPNM resulted in higher apparent ileal digestibility (AID) and standardized ileal digestibility (SID) values of the essential amino acids of methionine, lysine, leucine, and phenylalanine (p < 0.05). Moreover, the AID and SID values of the non-essential amino acids of FPNM were both higher than those of PNM, except for proline (p < 0.05). The AME was determined by the classic substitution method, and the results showed that fermentation had no effect on the AME value (p > 0.05). In conclusion, solid-state fermentation improved the nutritional value of PNM, and FPNM was a potential ingredient as an alternative protein source for broilers.

Valorization of agro-industrial wastes into animal feed through microbial fermentation: A review of the global and Ghanaian case

Agricultural and industrial activities around the world lead to the production of large quantities of agro-industrial wastes (e.g., peels of cassava, pineapple, plantain, banana, and yam, as well as rice husks, rice bran , corn husks, corn cobs, palm kernel cake, soybean meal, wheat bran, etc.). These agro-industrial wastes are discarded indiscriminately, thereby polluting the environment and becoming hazardous to human and animal health. Solid-state fermentation (SSF), a microbial fermentation process, is a viable, efficient approach that transforms discarded agro-industrial wastes into a plethora of useful value-added bioproducts. There is growing interest in the application of SSF in valorizing agro-industrial wastes for the production of fermented, protein-rich animal feed within the livestock industry. SSF reduces anti-nutritional factors whose presence hinders the digestibility and bioavailability of nutrients in agro-industrial wastes. Thus, the application of SSF improves the nutrient contents and quality of valorized agro-industrial wastes as animal feed. Fermented animal feed production may be safer, cheaper and enhance the overall growth performance and health of animals. SSF, therefore, as a strategic approach in a circular bioeconomy, presents economic and practical advantages that guarantee efficient recycling and valorization of agro-industrial wastes that ameliorate environmental pollution. This paper reviews the status of global and local Ghanaian biotransformation and valorization of agro-industrial wastes through SSF for the production of nutrient-rich animal feed.

Alternative Protein Sources and Novel Foods: Benefits, Food Applications and Safety Issues

The increasing size of the human population and the shortage of highly valuable proteinaceous ingredients has prompted the international community to scout for new, sustainable, and natural protein resources from invertebrates (e.g., insects) and underutilized legume crops, unexploited terrestrial and aquatic weeds, and fungi. Insect proteins are known for their nutritional value, being rich in proteins with a good balance of essential amino acids and being a valuable source of essential fatty acids and trace elements. Unconventional legume crops were found rich in nutritional, phytochemical, and therapeutic properties, showing excellent abilities to survive extreme environmental conditions. This review evaluates the recent state of underutilized legume crops, aquatic weeds, fungi, and insects intended as alternative protein sources, from ingredient production to their incorporation in food products, including their food formulations and the functional characteristics of alternative plant-based proteins and edible insect proteins as novel foods. Emphasis is also placed on safety issues due to the presence of anti-nutritional factors and allergenic proteins in insects and/or underutilized legumes. The functional and biological activities of protein hydrolysates from different protein sources are reviewed, along with bioactive peptides displaying antihypertensive, antioxidant, antidiabetic, and/or antimicrobial activity. Due to the healthy properties of these foods for the high abundance of bioactive peptides and phytochemicals, more consumers are expected to turn to vegetarianism or veganism in the future, and the increasing demand for such products will be a challenge for the future.

Valorization of Citrus Reticulata Peels for Flavonoids and Antioxidant Enhancement by Solid-State Fermentation Using Aspergillus niger CGMCC 3.6189

The bioactive components and bioactivities of citrus peel can be enhanced with microbial fermentation. Accordingly, this study investigated the ability of Aspergillus niger CGMCC3.6189 to accumulate flavonoids in Citrus reticulata peel powder (CRPP) by solid-state fermentation (SSF). Under the optimal SSF conditions including 80% moisture, 30 °C, pH 4.0, 4 × 10⁷ spores/g d.w. CRPP, and 192 h, the total phenolic content (TPC), total flavonoid content (TFC), and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging activities of fermented CRPP significantly increased by 70.0, 26.8, 64.9, and 71.6%, respectively. HPLC analysis showed that after fermentation, the contents of hesperidin, nobiletin, and tangeretin were significantly increased from 19.36, 6.31, and 2.91 mg/g to 28.23, 7.78, and 3.49 mg/g, respectively, while the contents of ferulic acid and narirutin were decreased under the optimal fermentation conditions. Fermentation time is one of the most important factors that affect the accumulation of flavonoids and antioxidant activity; however, extended fermentation time increased the darkness of CRPP color. Therefore, our study provides a feasible and effective SSF method to increase the bioactive components and the antioxidant activity of CRPP that may be used in food, nutraceutical, and medicinal industries.

Phenolic Profile, Antioxidant Activity and Amino Acid Composition of Moringa Leaves Fermented with Edible Fungal Strains

Solid-state fermentation (SSF) is widely recognised as a technique to increase the bioactive potential and nutritional value of plant materials. However, the effect of this biotreatment differs for individual substrates. This study aimed to evaluate the impact of SSF with filamentous fungi (Rhizopus, Aspergillus, and Neurospora) on a moringa leaf phenolic profile, antioxidant activity, and amino acid composition. A total of 43 phenolic compounds were determined in the dried leaves analysed by HPLC-ESI-TOF-MS. The leaves contained 11.79 mg/g of free phenolics: flavonols (80.6%, mainly quercetin and kaempferol glycosides), hydroxycinnamic acid derivatives (12.3%), vitexin and vicenin (6.9%), and a small amount of lignan (isolariciresinol isomers). The result of the 1-day fermentation was a slight enhancement in the concentration of individual free phenolics (flavones) and the antioxidant activity of the leaves. However, extending the incubation period caused a significant decrease in those parameters and cannot be recommended for obtaining a food fortificant from moringa leaves. In contrast, the 3-day fermentation with N. intermedia led to a 26% average accumulation of individual amino acids. Therefore, the SSF with Neurospora can be a promising method for improving the nutritional composition of moringa leaves and needs further investigation.