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A jeotgal-like product was processed from Chinook salmon (Oncorrhynchus tshawytscha) roe. Physicochemical, biochemical, and microbiological compositions were studied during 30 days of fermentation. Fermentation decreased water activity (a

Fresh apricots pre-treated by pulsed electric fields at different intensities [LPEF, 0.65 kV/cm, 100 Hz, 20 µs and total treatment time 30 s; HPEF1, 1.25 kV/cm, 100 Hz, 20 µs and total treatment time 30 s; HPEF2, 1.25 kV/cm, 100 Hz, 20 µs and total treatment time 60 s], along with controls [non-treated, non-treated and sulphite treated, and heat pre-treatment at 80 °C, for 10 min (HC)] and soaked in 0.2% sodium sulphite solution for 1 h and then were subject to hot air drying. The changes in drying rate, polyphenol oxidase, peroxidase, and β-carotene contents as well as antioxidant activity and colour in pre-treatment and hot air-dried apricot samples were investigated. PEF and heat treatments increased the drying rate of apricots. PEF treatments had no effect on the PPO activity and decreased the POD activity (p

The extraction of polyhydroxylated naphthoquinone (PHNQ) pigments from the shell and spines of the New Zealand sea urchin Evechinus chloroticus was evaluated using six different macroporous resins as an alternative to using organic solvent extraction alone. Four of the resins evaluated in this study (D4006, D4020, D101 and NKA-9) provided the best extraction of PHNQ pigments in terms of the overall adsorption and desorption of E. chloroticus PHNQ pigments from the resins. Organic solvents alone had a higher yield of PHNQs than the resins. The PHNQ composition was characterised by high-performance liquid chromatography (HPLC) with diode‐array detection and mass spectrometry. Five PHNQ compounds (spinochromes E, B, C, A and echinochrome A), and three aminated PHNQ compounds (spinamine E, echinamines A and B) were identified. The pigments were found to be prone to degradation on exposure to light, with the aminated PHNQ pigments being the least stable.

The effect of pulsed electric fields (PEF) at different field strengths (0.62, 1.25, 1.875 kV/cm) and frequencies (25, 50, 100 Hz) on total lipid extraction from hoki roe was investigated, along with the lipidomic profile (total lipid, phospholipid, fatty acid, phospholipid composition, and positional distribution of EPA and DHA). High PEF input (112 kJ/kg, 1.875 kV/cm and 100 Hz) yielded the highest total lipid (16.2% wet weight (WW)), and phospholipid (46 μmol/g WW) contents, without affecting n-3 fatty acid content (32%), and generated the highest LDPG, LPE, LPS and LPC contents (1.1, 0.41, 6.13 and 2.15 μmol/g WW, respectively). However, this PEF treatment resulted in sn-2 phospholipid EPA and DHA to be relocated to the sn-1,3 positions. Despite the good yield of n-3 fatty acids and PL, high PEF intensity treatment was found to result in negative structural changes in hoki roe lipids.

Two commercially available food grade fungal protease preparations (Fungal Protease 31,000 and Fungal Protease 60000) were found to hydrolyse bovine acid whey proteins but left the beta-lactoglobulin (β-Lg) intact under the processing conditions used. Comparative analysis before and after hydrolysis of bovine acid whey, by 1D- and 2D-PAGE, RP-HPLC and intact-mass mass spectrometry showed that the β-Lg remains intact and in high yield after hydrolysis by the fungal proteases. The β-Lg could be separated from the whey protein peptide hydrolysate by ultrafiltration. Subjecting whey fraction to hydrolysis with the fungal protease preparations provides a procedure, under relatively mild conditions, to generate a highly enriched β-Lg fraction. β-Lg is recognised as a valued material in the food, pharmaceutical and cosmetic industries due to its properties such as gelling and foaming. The enriched β-Lg preparation would also have application in areas such as nanoencapsulation.

Fungal protease FPII was found to hydrolyse sheep β-lactoglobulin (β-Lg), and the hydrolysate exhibited substantial antioxidant and ACE inhibition bioactivities. From analysis of the peptide sequences in the hydrolysate in relation to bioactivity, synthetic peptides corresponding to four regions of sequence in β-Lg (LAFNPTQLEGQCHV, DTDYKKYLLF, LDAQSAPLRVY and VEELKPTPE) were analysed for bioactivity. Additional synthetic peptides were designed to examine the bioactivity of different parts of the above four sequences, and the effect of amino acid substitutions on bioactivity. The results show that parts of the peptide sequences contribute differently to bioactivity and substitution of amino acids has a substantial effect on antioxidant and ACE inhibition activities.

The present study investigated the lipid profile (fatty acid profile, positional distribution of n-3 fatty acids and phospholipid content) of head and skin of three lean fishes (gurnard, ribaldo and snapper). Gurnard head (GH) and snapper head (SnH) were found to contain a higher amount of total lipid (5.9–6.3%) than other samples (1.2–3.9%) including a considerable amount of bioactive n-3 fatty acids such as EPA (GH = 9.05%; SnH = 5.06%), DPA (GH = 2.78% ; SnH = 2.93%) and DHA (GH = 12.8% ; SnH = 7.72%) in the polar lipid fraction. DHA was found to predominate in the sn-2 position for gurnard head and snapper head. Partial least squares discriminant analysis showed that both gurnard and snapper samples were positively correlated with the n-3 fatty acids (EPA, DPA and DHA). Gurnard and snapper head had higher phospholipid content than the skin. Therefore, among the studied samples, GH and SnH are the best source of bioactive n-3 phospholipids.

The physicochemical, biochemical and microbiological changes of karasumi-like Chinook salmon (Oncorrhynchus tshawytscha) roe were determined during 20 days of salted-drying processing. Colour parameters (L*, a*, and b*), water activity (aw) and the pH value decreased at the end of the processing. Total bacterial and LAB counts (log CFU/g) varied over the processing period. Saturated fatty acids, such as palmitic acid (C16:0) and stearic acid (C18:0), and unsaturated fatty acids such as palmitoleic acid (C16:1), oleic acid (C18:1), and arachidonic acid (C20: 4), were significantly decreased (p

The present study investigated phospholipid content, fatty acid composition and the positional distribution (sn-1,3 and sn-2) of n-3 fatty acids in four blue mackerel processing by-products (head, skin, roe, and male gonad). Total lipid was extracted using hexane/ethanol (1:2) and the analyses were carried out using NMR and GC-FID techniques. On the basis of g wet tissue, blue mackerel roe was a better source of phospholipids (38.6 µmol), compared to head (9.89 µmol), skin (13.5 µmol), and male gonad (10.0 µmol). Total lipid extracted from roe was found to have a higher proportion of n-3 fatty acids (44.4%) including EPA (11.3%) and DHA (27.5%), compared to head (total n-3 = 36.6%; EPA, 9.08%: DHA, 21.9%), skin (total n-3 = 34.8%; EPA, 9.63%; DHA, 19.5%) and male gonad (total n-3 = 42.5%; EPA, 12.1%; DHA, 24.7%). The proportion of EPA in the sn-2 position was substantially higher in fish roe (12.6%) compared to the other by-products (head, 1.91%; skin, 2.22%; male gonad, 2.02%). However, the DPA and DHA content in the sn-2 position did not vary significantly among the various parts (p > 0.05). Phospholipid esterified n-3 fatty acids were higher in roe (55.5%) compared to head (40.9%), skin (21.8%) and male gonad (32%). The present study suggests that blue mackerel roe is the best source of marine n-3 phospholipids among the blue mackerel commercially produced by-products.

This study used a novel extraction method (ETHEX) to extract the lipid content of King salmon head, skin and roe, and determined the lipid profiles using GC-FID, 13C NMR and 31P NMR spectroscopy. On a wet tissue basis, King salmon roe was found to contain the highest amount of phospholipid (26.53 µmol/g) and n-3 fatty acids (43.32%), followed by head (PL = 10.76 µmol/g; n-3 = 7.21%) and skin (PL = 4.98 µmol/g; n-3 = 8.23%). Total EPA (6.62%) and DHA (28.83%) content, along with the sn-2 positioned EPA (3.25%), DPA (1.36%) and DHA (16.35%) were also higher in roe compared with head and skin. The highest amount of EPA (7.99%) and DHA (34.47%) contents were found in the polar lipid fractions of roe, followed by skin (EPA = 4.19%; DHA = 25.95%) and head (EPA = 2.61%; DHA = 17.85%). This result suggests that salmon roe could be used for developing n-3 phospholipid enriched products.

The effect of pH (4, 5, 7, and 9) combined with either heat (60, 80°C for 10min) or pulsed electric fields (PEF) (1.4-1.8kV/cm, 260-690kJ/kg) treatments on the in vitro peptic digestion of ovomucin-depleted egg white was investigated. Protein digestibility, unaffected by 60°C heating, was increased by heating at 80°C, which caused protein aggregation and solution turbidity. Compared to ovalbumin and lysozyme, ovotransferrin was more susceptible to pepsinolysis. Susceptibility to pepsinolysis of ovalbumin and lysozyme was markedly enhanced by heating at 80°C, compared to either 60°C heating or PEF processing. MALDI-MS identified proteolytic fragments from ovalbumin and lysozyme, exhibiting varied resistance to pepsinolysis. PEF processing at ∼690kJ/kg and pH 4 increased protein digestibility to a similar level to that obtained after heating at 80°C, with negligible solution turbidity, showing potential for the production of digestible protein drinks with good consumer visual appeal owing to their clarity.

Squid pens were subjected to alkali hydrolysis to extract chitin and chitosan. Proteins present in the alkaline extraction wastewater were recovered at pH 3, 4, 5 and 6, and were subjected to hydrolysis by trypsin, pepsin and a bacterial protease called HT for 1, 2, 4 and 24h. Hydrolysis of the extracted proteins with either trypsin or HT generated more antioxidant activity than hydrolysis with pepsin. Higher ACE-inhibitory activity was generated in the trypsin and pepsin hydrolysates than in the HT hydrolysate. Squid pen protein recovered from chitosan processing waste alkaline solution can be a potential source of bioactive peptides for addition to foods. The antioxidant and ACE-inhibitory activities of the extracted proteins were initially low and increased upon incubation with the proteases. Pepsin generated significantly lower (P0.05) antioxidant activities compared to trypsin and HT, while trypsin and pepsin hydrolysates exhibited higher ACE-inhibitory activity than HT (P0.05).

Five commercially available food-grade microbial protease preparations were evaluated for their ability to hydrolyse meat myofibrillar and connective tissue protein extracts to produce bioactive peptides. A bacterial-derived protease (HT) extensively hydrolysed both meat protein extracts, producing peptide hydrolysates with significant in vitro antioxidant and ACE inhibitor activities. The hydrolysates retained bioactivity after simulated gastrointestinal hydrolysis challenge. Gel permeation chromatography sub-fractionation of the crude protein hydrolysates showed that the smaller peptide fractions exhibited the highest antioxidant and ACE inhibitor activities. OFFGEL electrophoresis of the small peptides of both hydrolysates showed that low isoelectric point peptides had antioxidant activity; however, no consistent relationship was observed between isoelectric point and ACE inhibition. Cell-based assays indicated that the hydrolysates present no significant cytotoxicity towards Vero cells. The results indicate that HT protease hydrolysis of meat myofibrillar and connective tissue protein extracts produces bioactive peptides that are non-cytotoxic, should be stable in the gastrointestinal tract and may contain novel bioactive peptide sequences.

Protease preparations from plant (papain and bromelain) and fungal (FP400 and FPII) sources were used to hydrolyze the red blood cell fractions (RBCFs) separated from deer, sheep, pig, and cattle abattoir-sourced blood. After 1, 2, 4 and 24 h of hydrolysis, the antioxidant and antibacterial activities of the peptide hydrolysates obtained were investigated. The increase in trichloroacetic acid-soluble peptides over the hydrolysis period was examined using the o-phthaldialdehyde (OPA) assay and the hydrolysis profiles were illustrated using SDS–PAGE. Papain generated RBCF hydrolysates exhibited higher ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) compared to those generated with bromelain, FP400 and FPII. At certain concentrations, 24 h hydrolysates of RBCF using FP400 and FPII were able to inhibit the growth of Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The results indicated that the use of proteases from plant or fungal sources can produce animal blood hydrolysates with antioxidant and antimicrobial activities.

This study reports a procedure for the simultaneous purification of glyco(caseino)macropeptide, immunoglobulin, lactoperoxidase, lactoferrin, α-lactalbumin and β-lactoglobulin from sheep cheese sweet whey, an under-utilized by-product of cheese manufacture generated by an emerging sheep dairy industry in New Zealand. These proteins have recognized value in the nutrition, biomedical and health-promoting supplements industries. A sequential fractionation procedure using economical anion and cation exchange chromatography on HiTrap resins was evaluated. The whey protein fractionation is performed under mild conditions, requires only the adjustment of pH between ion exchange chromatography steps, does not require buffer exchange and uses minimal amounts of chemicals. The purity of the whey protein fractions generated were analyzed by reversed phase-high performance liquid chromatography and the identity of the proteins was confirmed by mass spectrometry. This scalable procedure demonstrates that several proteins of recognized value can be fractionated in reasonable yield and purity from sheep cheese whey in one streamlined process.

This study investigated the bioactivities of polyhydroxyl-1,4-naphthoquinone (PHNQ) extracts from Evechinus chloroticus shell waste. PHNQs were extracted from E. chloroticus shells and spines using different solvents and the crude extracts were fractionated by HPLC. The antioxidant activity of the PHNQ extracts were evaluated by the DPPH, ABTS, ORAC and FRAP assays. Ethyl acetate was the best extraction solvent and spine extracts showed better antioxidant activity than shell extracts (p 0.05). The HPLC fraction containing spinochrome E showed the highest antioxidant activity (p 0.05). The Minimum Inhibitory Concentration of the PHNQ crude extracts and the HPLC fractions ranged from 250 to 2500 µg/mL depending on the PHNQ extract and microbial species tested. Treatment by PHNQ extracts resulted in alteration of the morphology of the microbial cell wall as observed by transmission electron microscopy. PHNQ extracts also exhibited anti-inflammatory activity in rats (ED

This research investigated the effects of pulsed electric fields (PEF) (1.4–1.7 kV/cm, 653–695 kJ/kg) and heating (60 and 80 °C for 10 min) at different pH (4, 5, 7, and 9) on the antioxidant and anti-inflammatory activity of ovomucin-depleted egg white (OdEW) after in vitro gastrointestinal hydrolysis. PEF and heating (80 °C for 10 min) at pH 4 enhanced the antioxidant activity of the whole hydrolysates, chemically determined using DPPH and ORAC assays. Furthermore, the anti-inflammatory activity of protein hydrolysates was assessed in lipopolysaccharide-stimulated HT-29 cells using ELISA assay. PEF and heating at pH 4 enhanced the anti-inflammatory activity of the whole hydrolysates dose-dependently. Hydrolysates at 1 mg/ml showed similar inhibition (35.5% and 35.9%) of interleukin-8 production, due to PEF treatment and heating (80 °C for 10 min), respectively. Results indicated that prior PEF treatment can analogously enhance both antioxidant and anti-inflammatory activity of OdEW hydrolysates to heating, with potentially reduced thermal input.

Plasma separated from deer, sheep and pig blood, obtained from abattoirs, was hydrolysed using protease preparations from plant (papain and bromelain) and fungal (FP400 and FPII) sources. Antioxidant and antimicrobial activities of the peptide hydrolysates obtained after 1, 2, 4 and 24h of hydrolysis, were investigated. The release of trichloroacetic acid-soluble peptides over the hydrolysis period was monitored using the o-phthaldialdehyde (OPA) assay, while the hydrolysis profiles were visualised using SDS-PAGE. The major plasma proteins in the animal plasmas were identified using MALDI-TOF-TOF MS. Hydrolysates of plasma generated with fungal proteases exhibited higher DPPH radical-scavenging, oxygen radical-scavenging capacity (ORAC) and ferric reducing antioxidant power (FRAP) than those generated with plant proteases for all three animal plasmas. No antimicrobial activity was detected in the hydrolysates. The results indicated that proteolytic hydrolysis of animal blood plasmas, using fungal protease preparations in particular, produces hydrolysates with high antioxidant properties.

Two plant enzyme extracts from kiwifruit and asparagus were evaluated for their ability to hydrolyse commercially available substrates and proteins present in both beef connective tissue and topside myofibrillar extracts. The results show significant differences in protease activity depending on the assay used. Protease assays with connective tissue and meat myofibrillar extracts provide a more realistic evaluation of the potential of the enzymes for application in meat tenderization. Overall, the kiwifruit protease extract was found to be more effective at hydrolysing myofibrillar and collagen proteins than the asparagus protease extract. The two protease extracts appeared to target meat myofibrillar and collagen proteins differently, suggesting the potential of a synergistic effect of these proteases in improving the tenderness of specific cuts of meat, based on their intrinsic protein composition.

Four protease preparations from plant and fungal sources (papain, bromelain, FP400 and FPII) were used to hydrolyse plasma which was separated from slaughterhouse cattle blood. The o-phthaldialdehyde assay was used to follow the release of TCA-soluble peptides over a 24h period. Hydrolysis profiles were displayed using SDS-PAGE. The in vitro antioxidant and antimicrobial activities of the hydrolysates were determined. The results showed that hydrolysates of cattle plasma generated with fungal protease FPII had higher antioxidant activities. Overall than hydrolysates generated with papain, bromelain and FP400. None of the hydrolysates demonstrated antimicrobial activity. The FPII peptide hydrolysate was fractionated using gel permeation chromatography, OFFGEL isoelectric focusing and RP-HPLC. The RP-HPLC fraction with highest antioxidant activity contained 15 novel peptide sequences. The use of protease FPII to hydrolyse cattle plasma resulted in a hydrolysate with high antioxidant properties and unique peptide sequences.

Physicochemical (zeta potential (ζ), conductivity, surface hydrophobicity (H0), protein solubility (PS)) and emulsifying (emulsion capacity (EC), droplet size, polydispersity (PDI), emulsifying activity (EAI), and stability (ESI) indexes) properties of alkali-(A-FPC), enzymatic-(E-FPC), and enzymatic-solvent-(ES-FPC) extracted protein concentrates from flaxseed meal (FM) were investigated and compared to commercial pea protein concentrate (PPC). The yield, composition, and properties of the protein concentrates were significantly influenced by the methods of extraction. All emulsions were similar in polydispersity with mono-modal droplet distribution and size of ⩽0.43μm that carried a net negative charge at neutral conditions (pH 7.0). A-FPC showed significantly higher H0 (66.14) than that of ES-FPC (52.63), and E-FPC (43.27) and was comparable to PPC (68.47). The highest solubility was found for E-FPC followed by A-FPC at neutral pH. A-FPC displayed significantly (p

Four commercially available plant preparations containing respectively papain, bromelain, actinidin and zingibain were evaluated for their ability to hydrolyse proteins present in both beef connective tissue and topside myofibril extracts. The results show significant differences in protease activity depending on the assay used and that protease assays with connective tissue and meat myofibril extracts provide a realistic evaluation of the potential of the enzymes for application in meat tenderisation. The actinidin protease preparation was found to be most effective at hydrolysing beef myofibril proteins and the zingibain protease preparation most effective at hydrolysing connective tissue proteins. This indicates the potential of these proteases for targeting specific tenderising applications, in contrast to trying to achieve control of tenderisation with the more active papain and bromelain proteases.

Hemp protein isolates (HPIs) were hydrolysed by proteases (AFP, HT, ProG, actinidin and zingibain). The enzymatic hydrolysis of HPIs was evaluated through the degree of hydrolysis and SDS-PAGE profiles. The bioactive properties of the resultant hydrolysates (HPHs) were accessed through ORAC, DPPḢ scavenging and ACE-inhibitory activities. The physical properties of the resultant HPHs were evaluated for their particle sizes, zeta potential and surface hydrophobicity. HT had the highest rate of caseinolytic activity at the lowest concentration (0.1 mg mL(-1)) compared to other proteases that required concentration of 100 mg mL(-1) to achieve their maximum rate of caseinolytic activity. This led to the highest degree of hydrolysis of HPIs by HT in the SDS-PAGE profiles. Among all proteases and substrates, HT resulted in the highest bioactivities (ORAC, DPPḢ scavenging and ACE-inhibitory activities) generated from alkali extracted HPI in the shortest time (2 h) compared to the other protease preparations.