In-vitro colonic fermentation of Kakadu plum (Terminalia ferdinandiana) fruit powder: Microbial biotransformation of phenolic compounds and cytotoxicity.

Kakadu plum (Terminalia ferdinandiana) (KP) is an indigenous fruit used as a functional ingredient in powdered form. Three KP doses (1, 2.5 and 5 g) were digested in a dynamic in vitro gut digestion model over 48 h. Faecal water digests from the colonic reactors were assessed for total soluble polyphenols (TSP), ferric reducing antioxidant power (FRAP), phenolic metabolites and short-chain fatty acids (SCFAs). Effects of digests on cell viability were tested against Caco-2 intestinal and HepG2 hepatic cells. All doses of KP fermentation produced castalagin, corilagin, chebulagic acid, chebulinic acid, and gallic acid. TSP and FRAP significantly increased in 5 g KP digests at 0 and 48 h of fermentation. SCFA concentrations significantly increased after 48 h. Cytotoxic effects of 2.5 and 5 g KP digests diminished significantly after 12 h. Overall, colonic fermentation increased antioxidant activity and polyphenolic metabolites of 5 g KP powder for 48 h.

In Vitro Antioxidant Activity, Bioaccessibility, and Thermal Stability of Encapsulated Strawberry Fruit (Fragaria × ananassa) Polyphenols.

Bioactive compounds in red fruits, such as strawberries, are vulnerable to digestion, and encapsulation has become an alternative for their protection. This study aims at encapsulating strawberry juice (SJ) by freeze-drying with pea protein and okra mucilage (SJPO), pea protein and psyllium mucilage (SJPP), and pea protein, psyllium mucilage, and okra mucilage (SJPPO) and investigating the in vitro release. The highest encapsulation efficiency was observed in capsule SJPPO (95.38%) and the lowest efficiency in SJPO (82.45%). Scanning electron microscopy revealed an amorphous glassy structure for the structure of the strawberry microcapsules, and X-ray diffraction confirmed that observation. However, X-ray diffraction further showed that SJPPO was crystalline, indicating a tighter crosslinking density than the other microcapsules. Fourier transform infrared spectroscopy showed peaks at 3390 and 1650 cm-1, confirming the presence of polyphenols and polysaccharides in the strawberry microcapsules. Thermal stability was higher for SJPPO, and the observed thermal transitions were due to the bonds formed between the polymers and polyphenols. Pelargonidin 3-glucoside, cyanidin 3-glucoside, cyanidin, delphinidin, malvidin 3-glucoside, ellagic acid, chlorogenic acid, catechin, and kaempferol were identified in the strawberry microcapsules. Digestion affected the compounds' content; the bioaccessibility for SJ was 39.26% and 45.43% for TPC and TAC, respectively. However, encapsulation improved the bioaccessibility of both TPC (SJPP, 51.54%; SJPO, 48.52%; and SJPPO, 54.39%) and TAC (SJPP, 61.08%; SJPO, 55.03%; and SJPPO, 71.93%). Thus, encapsulating pea protein isolate, psyllium mucilage, and okra mucilage is an effective method to facilitate targeted release and preserve the biological activities of fruits.

Nutritional and techno-functional properties of Australian Acacia seed flour: Effects of roasting on chemical composition, physicochemical properties, and in vitro digestibility and intestinal iron absorption.

Acacia seed (AS) is rich in protein and iron but contains protease inhibitors that can reduce protein digestibility (PD). The seeds are generally roasted prior to consumption, although no information on the PD of roasted AS is available. This study investigated the effect of roasting time (5, 7 and 9 min at 180 °C) on the chemical composition, physicochemical properties, and in vitro PD and intestinal iron absorption of three wild harvested Australian AS species, Acacia victoriae, A. coriacea and A. cowleana. Roasting A. victoriae and A. coriacea seeds for 7 min significantly increased PD in the seeds by 36 and 61 %, respectively. A 9-min roasting time was required to achieve 75 % reduction in trypsin inhibitor activity in A. coriacea seed, while a shorter roasting time (RT) was sufficient to achieve similar reduction rates in the other two Acacia species. Among the functional properties, water and oil absorption capacities were significantly enhanced as RT increased. The starch granules in 7- and 9-min roasted A. victoriae seed flour detached from the protein matrix while random coil increased in 7-min roasted A. victoriae and 9-min roasted A. coriacea and A. cowleana, thus, contributing to enhanced PD. Although the SDS-PAGE in 7- and 9-min roasted A. cowleana samples showed reductions in the intensity of bands for high molecular weight proteins, PD was not affected by RT. However, intestinal iron absorption was not significantly affected by roasting as compared to raw digesta samples. Compared to commercial roasted Acacia seed, the considerably shorter RT used in this study improved PD in the AS flour with less adverse effects on techno-functional properties.

Effects of incorporating processed Acacia seed as an emulsifying agent on the quality attributes of beef sausage.

In this study, partial or full replacement of 6% soy protein isolate (SPI) with 2, 4 and 6% roasted Acacia seed flour (ASRo) and Acacia seed protein concentrates (ASPC) in emulsified beef sausage were investigated. Emulsion stability and cooking loss were lower in samples formulated with ASPC at all levels and control samples compared to ASRo formulated samples. ASRo generated softer and less chewy sausages than ASPC. Cooked 2% ASPC sausages had similar L* and a* values as the control but with lower colour difference (ΔE) values that were similar to cooked 6% SPI sausages' values. An organized protein network structure was observed in the sausages formulated with ASPC at all levels and in the control samples. Therefore, ASPC, particularly at 2 and 4% inclusion, can be used as a functional ingredient to prepare emulsified beef sausages with good quality attributes.

Effect of frozen storage on the biochemical composition of five commercial freshwater fish species from River Nile, Sudan.

Postharvest processing and preservation of fish have great influence on fish quality and consumption. Freshwater fish in Sudan are facing problems related to bad handling and improper storage which reduce their quality. This study investigated the changes in the chemical composition, mineral contents, pH and acid value during storage (-18°C) of five commercial fish species (Bagras bayad, Lates niloticus L., Mormyrus casahive L., Oreochromis nilotica L., and Synodrontis schall) from the River Nile coast of Sudan. The fish species are rich in protein (17.22%-23.60%) but have low fat and ash contents. Frozen storage of the fishes for 45 days reduces their protein contents while the fat and ash contents were increased (p ≤ .05). Potassium and iron are the predominant major and trace minerals and their values were increased with storage period. The pH range from 5.74 (O. niloticus) to 6.24 (B. bayad) while acid value range from 0.02 (M. casahive) to 0.12 (L. niloticus). Both pH and acid values increased with storage period. In conclusion, storage of these fish species for up to 45 days did not adversely affect their nutritional value.

Correction: Shelat, K.J.; et al. Overall Nutritional and Sensory Profile of Different Species of Australian Wattle Seeds (Acacia spp.): Potential Food Sources in the Arid and Semi-Arid Regions. Foods 2019, 8, 482.

The authors wish to make the following correction to the paper [1]:The title of Table 3 "Amino acid (g/100 g dry weight) profile of four different species of wattle seeds" should be changed to "Amino acid (mol% dry weight) profile of four different species of wattle seeds" [...].

Mid-Infrared Spectroscopy as a Rapid Tool to Qualitatively Predict the Effects of Species, Regions and Roasting on the Nutritional Composition of Australian Acacia Seed Species.

In recent times, the popularity of adding value to under-utilized legumes have increased to enhance their use for human consumption. Acacia seed (AS) is an underutilized legume with over 40 edible species found in Australia. The study aimed to qualitatively characterize the chemical composition of 14 common edible AS species from 27 regions in Australia using mid-infrared (MIR) spectroscopy as a rapid tool. Raw and roasted (180 °C, 5, 7, and 9 min) AS flour were analysed using MIR spectroscopy. The wavenumbers (1045 cm-1, 1641 cm-1, and 2852-2926 cm-1) in the MIR spectra show the main components in the AS samples. Principal component analysis (PCA) of the MIR data displayed the clustering of samples according to species and roasting treatment. However, regional differences within the same AS species have less of an effect on the components, as shown in the PCA plot. Statistical analysis of absorbance at specific wavenumbers showed that roasting significantly (p < 0.05) reduced the compositions of some of the AS species. The results provided a foundation for hypothesizing the compositional similarity and/or differences among AS species before and after roasting.

Nutritional, anti-nutritional, antioxidant, physicochemical and functional characterization of Australian acacia seed: effect of species and regions.

BACKGROUND: Acacia seed (AS) is an underutilized legume widely distributed in the world, with majority of the species (>70%) found in Australia. Generally, the seeds are not only rich in protein, dietary fibre and potassium, but also possess anti-nutritional compounds. In recent years, there have been an increase in the cultivation of some Australian acacia species such as Acacia victoriae, Acacia cowleana and Acacia coriacea from different regions. However, there is limited information on the composition, anti-nutrients, antioxidant and functional properties of flour from these widely grown Australian AS species. Thus, the present study aimed to assess the properties of these Australian AS species from different geographical regions. RESULTS: The A. cowleana and A. coriacea were characterized by high protein, fat, potassium and soluble carbohydrate. However, higher starch and fibre contents were present in A. victoriae. Greater amounts of anti-nutrients, total phenolics and flavonoids were found in A. cowleana and A. coriacea seeds, whereas A. victoriae had higher 2,2-diphenyl-1-picrylhydrazyl radical-scavenging capacity. A. victoriae and A. coriacea demonstrated the highest water absorption and solubility index, respectively. However, A. cowleana showed the highest oil absorption index. There was less variation in the composition and properties within species from different regions. CONCLUSION: All samples showed promising nutritional characteristics, although with sufficient diversity to indicate that Australian acacia seeds can be utilized to develop a range of new (functional) food products. Overall, the information obtained will help the food industries with the selection of AS species for food application.

Acacia seed proteins: Low or high quality? A comprehensive review.

The popularity of adding value to indigenous plant protein sources has increased due to the rise in the world population, high costs of animal protein as compared to plant proteins, and an increase in the consumer awareness of the nutritional and functional roles of dietary plant protein. Seeds of acacia plants (containing over 1,350 species) have considerable amount of protein (18.25% to 35.5%) and nutritionists have shown great interest in assessing the quality and functionality of proteins from these protein-rich plants. In this review, the overall nutritional and health-promoting properties of acacia seed (AS) species are introduced. Extraction, quality, and functional properties of proteins from different AS species are discussed. Furthermore, anti-nutritional components and protease inhibitors present in AS species and the effects of processing methods applied to lower the levels of anti-nutrients are also discussed. Previous applications of AS in food formulations are highlighted. This review aims to provide updated findings that have been reported on AS proteins and to highlight areas for further studies in order to increase the utilization potential of the seeds.

Optimization of ultrasound-assisted extraction of phenolic compounds and antioxidant activity from Argel (Solenostemma argel Hayne) leaves using response surface methodology (RSM).

In this study, phenolic compounds were extracted from Argel leaves using an ultrasound-assisted extraction (UAE) method. The extraction parameters (sonication temperature, time, and ethanol concentration) were optimized using a response surface methodology (Box-Behnken design), in order to maximize the total phenolic content (TPC) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity of Argel leaf extracts (ALEs). The phenolic compounds of the ALEs obtained under optimized conditions were also identified. The optimum UAE conditions for achieving maximum TPC (72.27 g gallic acid equivalents kg-1 DW) and DPPH scavenging activity (86.15%) were a 60 °C temperature, a 37.07 min duration, and a 39.14% ethanol concentration. Under these conditions, the experimental values of TPC and DPPH scavenging activity were 73.02 g GAE kg-1 and 85.56%, respectively, which agreed with the predicted values. In addition, the major phenolic acids found in ALEs under the optimized extraction conditions were sinapic, p-coumaric, and ferulic acid. Overall, the findings of this study demonstrated the suitability of UAE and the success of RSM in optimizing the extraction conditions of bioactive compounds from ALEs.

Assessment of oxidative stability and physicochemical, microbiological, and sensory properties of beef patties formulated with baobab seed (Adansonia digitata) extract.

The present study was conducted to evaluate the oxidative stability and the physicochemical, microbiological, and sensory properties of beef patties formulated with different concentrations (1%, 2%, and 3%) of baobab seed extract (BSE) during storage at 4 °C. The BSE contained a considerable number of phenolic compounds and exhibited antioxidant and antimicrobial activities (both on gram-positive and negative bacteria). The chemical composition of the patties was not altered by BSE treatment. However, the addition of 2% and 3% BSE improved the lipid stability and enhanced the antioxidant activity of beef patties during storage. Furthermore, the shelf-life of patties formulated with 2% and 3% of BSE increased from 7 days (control group) to 21 days. Moreover, the patties formulated with BSE received overall acceptability in the sensory evaluation. In conclusion, the inclusion of 2% or 3% BSE could be recommended as a natural antioxidant additive in beef patties.

Overall Nutritional and Sensory Profile of Different Species of Australian Wattle Seeds (Acacia spp.): Potential Food Sources in the Arid Semi-Arid Regions.

Wattle seed (Acacia spp.) is a well-known staple food within indigenous communities in Australia. A detailed investigation of the overall nutritional and sensory profile of four abundant and underutilized Acacia species-A. coriacea, A. cowleana, A. retinodes and A. sophorae-were performed. Additionally, molecular weight of protein extracts from the wattle seeds (WS) was determined. The seeds are rich in protein (23-27%) and dietary fibre (33-41%). Relatively high fat content was found in A. cowleana (19.3%), A. sophorae (14.8%) and A. retinodes (16.4%) with oleic acid being the predominant fatty acid. The seeds contained high amounts of essential amino acids (histidine, lysine, valine, isoleucine and leucine). A. coriacea is rich in iron (43 mg/kg), potassium (10 g/kg) and magnesium (1.7 g/kg). Pentose (xylose/arabinose), glucose, galactose and galacturonic acids were the major sugars found in the four species. Raw seeds from A. sophorae, A. retinodes and A. coriacea have the highest protein molecular weight, between 50-90 kDa, 80 kDa and 50-55 kDa, respectively. There was variation in the sensory profile of the WS species. This study showed that the four WS species have good nutritional value and could be included in human diet or used in food formulations.

Effect of Traditional Processing on the Nutritional Quality and in vivo Biological Value of Samh (Mesembryanthemum forsskalei Hochst) Flour.

Roasting improved the determined protein and carbohydrate content of the flour compared to raw flour (p < 0.05). Baking enhanced the determined moisture and ash content of the flour compared to all treatments (p < 0.05). Similar amino acid content was found in both raw and treated flours with glutamic acid, glycine, arginine, and aspartic acid being predominant. Cooking reduced the total aromatic and non-essential amino acid content whereas roasting reduced the total essential amino acid content of samh flour. All treatments significantly (p < 0.05) decreased the antinutritional factors compared to untreated raw flour. Baking decreased the trypsin inhibitor activity by almost 98.7% whereas cooking reduced phytate and tannin content by 38.5% and 10.8, respectively. Roasting and baking significantly (p < 0.05) improved the in vitro protein digestibility of the flour. In vivo, the true faecal nitrogen digestibility of rats was significantly (p < 0.05) enhanced by all treatments. Baking and cooking increased (p < 0.05) the net protein utilization and biological value of the flour. Overall, the treatments improved the nutritional quality of samh flour.

Quality attributes of Kisra prepared from sorghum flour fermented with baobab fruit pulp flour as starter.

Kisra, a fermented sorghum flat bread, was prepared from two sorghum genotypes termed Wad-Ahmed (high tannin) and Tabat (low tannin) in Sudan that has been fermented with different starter levels [20, 50, 75 and 100 g of fermented baobab fruit pulp flour (FBFPF)/100 g flour]. Chemical composition, antinutritional factors, mineral extractability, ascorbic acid, in vitro protein (IVPD) and starch digestibilities (IVSD) of Kisra were determined. Preparation of Kisra with the sorghum genotypes fermented with higher levels of FBFPF enhanced the protein, fiber, fat, ash, and minerals contents and their extractability (P ≤ 0.05). Maximum amino acids contents were found in Kisra prepared from Tabat sorghum flour fermented with 100 g FBFPF/100 g flour. Ascorbic acid, IVPD and IVSD of Kisra from both genotypes increased with FBFPF levels, with a concomitant decrease in phytate and tannin contents (P ≤ 0.05). Sensory attributes of the Kisra were enhanced in Tabat and Wad-Ahmed sorghum genotypes prepared with 50 and 100 g FBFPF/100 g flour, respectively. Application of FBFPF is known to be an effective traditional starter, and it could improve the nutritional quality of Kisra bread.

The effect of Acacia nilotica seed extract on the physicochemical, microbiological and oxidative stability of chicken patties.

The present study investigates the effect of Acacia seed water extract (ASWE) at four levels (0, 50, 100, 150 mg/100 mL) in triplicate batch on the shelf-life and quality of chicken patties. Flavones, mainly (+)-catechin, were the predominant phenolic compounds in ASWE with high antioxidant activity. ASWE showed greater inhibition effects against gram-positive bacteria than gram-negative bacteria. ASWE incorporation had no significant effects on the chemical composition of chicken patties. The microbial load, and thiobarbituric acid reactive substances of chicken patties significantly decreased (P ≤ 0.05) and reached minimum values at 150 mg/100 mL but the pH decreased slightly. The cooking properties were significantly improved (P ≤ 0.05) at 150 mg/100 mL. Moreover, ASWE at high level (150 mg/100 mL) significantly (P ≤ 0.05) enhanced total phenolic content and free radical scavenging activity of chicken patties. The results showed that chicken patties with ASWE had better quality attributes compared to the unformulated. Shelf-life of chicken patties can therefore be prolonged for 15 days in refrigerated storage using ASWE especially at high concentration (150 mg/100 mL).

Physicochemical, nutritional, functional, rheological, and microbiological properties of sorghum flour fermented with baobab fruit pulp flour as starter.

Two sorghum genotypes termed Wad-Ahmed (high tannin) and Tabat (low tannin) in Sudan were fermented with different starter levels (0%, 25%, 50%, 75%, and 100%) of fermented baobab fruit pulp flour (FBFPF). Chemical composition, antinutrients, extracted minerals, and the microbiological, physicochemical, functional, rheological, and pasting properties from the fermented flours were determined. Fermentation of both genotypes with higher levels of FBFPF starter enhanced protein, fiber, ash, and major mineral contents and extractability (p ≤ 0.05). Total acidity, bulk density, rheological properties, in vitro protein, and starch digestibility of both genotypes increased with FBFPF levels, with a concomitant decrease in pH, phytate and tannin contents, and water and fat absorption capacities (p ≤ 0.05). Microbial loads, especially lactic acid bacteria, increased with increasing FBFPF starter levels in both genotypes. Use of FBFPF as a starter in the fermentation of sorghum flour can improve the nutritional value of sorghum. This could be usefully applied to the food industry for the development of fermented sorghum products.

Enzyme activity, sugar composition, microbial growth and texture of fresh Barhi dates as affected by modified atmosphere packaging.

The effects of modified atmosphere packaging (MAP) on various physicochemical quality attributes of fresh Barhi dates at the Khalal (yellow) stage were studied. Polypropylene (PP) and polyethylene (PE) plastic with varied perforation sizes (0, 50, 100 and 150 µm) were evaluated for storage of date fruits at temperatures of 1, 5, 15 and 25 °C up to 45 days. MAP showed significant effects on fruit quality. PP date packages perforated with 150-µm perforations and stored at 5 °C had the lowest acidity and microbial load. Dates packed in PE exhibited higher pectin methylesterase (PME) and polyphenol oxidase (PPO) activities than dates packed in PP. Dates stored in nonperforated packages had the highest PME, PPO and invertase activities. The maximum fructose and glucose contents were observed in PP-packaged dates stored at 15 °C. Analysis of the interactions of several MAP variables revealed temperature as the major variable controlling the quality of dates. The findings showed that MAP can be effectively employed to preserve the quality and improve the shelf life of Barhi dates using PP with 150-µm perforations as the packaging material during storage for 2 weeks at 5 °C.

Effect of Argel (Solenostemma argel) leaf extract on quality attributes of chicken meatballs during cold storage.

This study aimed to evaluate the antioxidant activity of Argel leaf water extract (ALWE) and its effect at different concentrations (0, 5, 10, and 20 mg/100 mL) on the antioxidant, antimicrobial, physicochemical, and sensory attributes of chicken meatballs during cold storage. ALWE contained substantial quantities of total phenolic content (TPC), anthocyanin, and exhibited high DPPH scavenging activity. ALWE incorporation in chicken meatballs had a varying effect on the chemical composition and sensory attributes of the product. However, ALWE incorporation at high concentration decreased the protein content of cooked meatballs and reduced fat content in both raw and cooked balls. Increased ALWE concentration in chicken meatballs lowered the pH, microbial load, and thiobarbituric acid reactive substances. Furthermore, ALWE raised the TPC and DPPH scavenging activity of chicken meatballs. Throughout the storage period, chicken meatballs formulated with ALWE showed better quality attributes than non-formulated chicken meatballs. In conclusion, ALWE can be employed as a functional ingredient for improved health benefits and shelf-life extension of chicken meatballs.

Nutritional, physicochemical, and functional properties of protein concentrate and isolate of newly-developed Bambara groundnut (Vigna subterrenea L.) cultivars.

Bambara groundnut is an indigenous African vegetable grown mainly for human food and animal feed due to its high protein content. Different factors like varieties and origin can influence the chemical composition of Bambara groundnut cultivars. Therefore, the aims of this study are to produce defatted flour and protein concentrate from newly developed Bambara groundnut cultivars [Accessions No: TVSU 5 - Bambara Groundnut White (BGW) and TVSU 146 - Bambara Groundnut Brown (BGB)] and compare their nutritional, physicochemical, and functional properties with market sample [Bambara groundnut commercial (BGC)]. Higher protein content was observed in BGW (20.73%) and BGB (20.14%) as compared to BGC (18.50%). Also, the fat and ash contents of BGB and BGW were higher than that of BGC. Also, the new varieties were found to contain higher levels of some essential fatty acids such as linoleic and linolenic acids. The concentration of thiamine, riboflavin, niacin, pantothenic, ascorbic acids, pyrodoxine, alpha tocopherol, and vitamin K were also significantly higher in the two new varieties. The new varieties were good sources of magnesium, calcium, iron, manganese, sodium, and potassium. The oil and water absorption and swelling capacities of whole, defatted, and protein concentrate flour of the new varieties increase with increase in temperature. The defatted flour and protein concentrate of brown Bambara groundnut was found to exhibit high emulsifying activity and stability at different pH's and salt concentrations. The new varieties possess significantly higher foaming capacity and stability than the commercial variety. The results obtained from this study have shown the potential for the industrial and household use of the new Bambara groundnut cultivars into shelf stable protein products and could be a useful ingredient in food formulations.

Thermosonication process for optimal functional properties in carrot juice containing orange peel and pulp extracts.

Aqueous extracts of orange peel and pulp with high total phenolic contents (TPC) (25.94 and 11.38 mg GAE/g extracts, respectively) were employed in the formulation of functional carrot juice and functional juices were treated using thermosonication process. In accordance with Box-Behnken design, 17 runs with 3 variables and 3 levels was applied for the optimization of the carrot juice with peel (CJPL) and pulp (CJPP) extracts. Overlaid contour plots prediction showed that the optimal conditions for CJPL were 125 mL juice volume, 6.50 min ultrasound process time and 52.78 °C ultrasound process temperature for maximum TPC (30.25 mg GAE/100 mL) and DPPH scavenging activity (61.22%). Sample CJPP has maximum TPC (28.94 mg GAE/100 mL) and DPPH activity (55.87%) under optimal ultrasound process conditions of 125 mL juice volume, 5.04 min and 59.99 °C ultrasound process time and temperature, respectively. Optimization of thermosonication showed significant improvements in the quality of functional carrot juice.