Avocado seed by-product uses in emulsion-type ingredients with nutraceutical value: Stability, cytotoxicity, nutraceutical properties, and assessment of in vitro oral-gastric digestion.

The avocado industry obtains 20-30% of the total by-products (peels and seeds). However, byproducts can be uses as sources of economic nutraceutical ingredients with functional potential. This work developed emulsion-type ingredients from avocado seed to evaluate its quality, stability, cytotoxicity, and nutraceutical properties before/after in vitro oral-gastric digestion. Ultrasound lipid extraction achieved an extraction yield of up to 95.75% compared with Soxhlet conventional extraction (p > 0.05). Six ingredients' formulations (E1-E6) were stable for up to day 20 during storage, preserving their antioxidant capacity and displaying low in vitro oxidation compared to control. None of the emulsion-type ingredients were considered cytotoxic according to the shrimp lethality assay (LC50 > 1000 µg/mL). Ingredients E2, E3, and E4 generated low lipoperoxides' concentrations and high antioxidant capacity during the oral-gastric stage. The 25 min-gastric phase showed the highest antioxidant capacity and low lipoperoxidation. Results suggested avocado seed-derived could be used to develop functional ingredients with nutraceutical properties.

In vitro digestibility of dietary proteins and in vitro DIAAS analytical workflow based on the INFOGEST static protocol and its validation with in vivo data.

The FAO recommends the digestible indispensable amino acid score (DIAAS) to determine protein quality in foods, preferably tested in vivo. Here, the INFOGESTin vitrodigestion protocol was applied and supplemented with an analytical workflow allowing the assessment of protein digestibility and DIAAS calculation. The protocol was applied to selected samples WPI, zein, collagen, black beans, pigeon peas, All-Bran®, and peanuts. The total protein digestibility, digestibility of individual amino acids (AA), and DIAAS values were established and compared with in vivo data for the same substrates. Total protein digestibility (total Nitrogen, r = 0.7, P < 0.05; primary amines (OPA), r = 0.6, P < 0.02; total AA, r = 0.6, P < 0.02) and digestibility of individual AA (r = 0.6, P < 0.0001) were in good agreement, between in vitro and in vivo, with a mean difference of 1.2 %. In vitro DIAAS was highly correlated with DIAAS obtained from in vivo true ileal digestibility values (r = 0.96, R2 = 0.89, P < 0.0001) with a mean difference of 0.1 %.

Antiulcerative Activity of Milk Proteins Hydrolysates.

Several studies have shown the protective effect of dairy products, especially α-lactalbumin and derived hydrolysates, against induced gastric ulcerative lesions. The mucus strengthening represents an important mechanism in the defense of gastrointestinal mucosa. Previously, a hydrolysate from casein (CNH) and a hydrolysate from whey protein concentrate rich in ß-lactoglobulin (WPH) demonstrated a stimulatory activity on mucus production in intestinal goblet cells. The aim of this work was to evaluate the possible antiulcerative activity of these two hydrolysates in an ethanol-induced ulcer model in rats. All tested samples significantly reduced the ulcerative lesions index (ULI), compared with the saline solution, using doses of 300 and 1000 mg kg-1 body weight with decreases up to 66.3% ULI. A dose-response relationship was found for both hydrolysates. The involvement of endogenous sulfhydryl (SH) groups and prostaglandins (PGs) in the antiulcerative activity was evaluated using their blockage. The antiulcerative activity of WPH showed a drastic decrease in presence of N-ethylmaleimide (from 41.4% to 9.2% ULI). However, the CNH antiulcerative properties were not significantly affected. The cytoprotective effect of WPH appears to depend on a PG-mediated mechanism. In conclusion, CNH and WPH demonstrated in vivo antiulcerative properties and represent a promising alternative as protectors of the gastric mucosa.

Anti-Inflammatory and Anti-Nociceptive Activities of Native and Modified Hen Egg White Lysozyme.

Persistent inflammatory conditions can have severe pathological consequences. Although the use of nonsteroidal anti-inflammatory drugs (NSAIDs) is effective, it has side effects, particularly at the gastrointestinal level. There is then a high interest to identify natural anti-inflammatory compounds with no side effects. The anti-inflammatory and anti-nociceptive activities of hen egg lysozyme (LZ), both in its native form and modified by heat treatment, chemically or by enzymatic digestion have been tested in this study. The carrageenan-induced model in mice using native LZ or modified LZ has been applied. It was observed that LZ denatured by heat treatment at pH 6.0 presented 39.47% of inhibition of paw edema when administered at 30 mg/kg. LZ denatured with DL-dithiothreitol (DTT) presented a significant result of 42.10% inhibition of paw edema when administered at 30 mg/kg of animal weight. Modified LZ showed anti-inflammatory capacity comparable with the activity of the positive control dexamethasone. A classical model of acetic acid-induced abdominal writhing tests in mice was used to assess anti-nociceptive activity of native LZ and denatured heat treatment LZ and denatured chemical agent LZ. Finally, hydrolyzed native LZ presented 48% of inhibition of abdominal writhing in mice. Modified LZ with heat, chemical, and hydrolysis presented anti-inflammatory and anti-nociceptive activities independently of their natural enzymatic activity. These novel data point out the potential use of denatured and digested LZ as therapeutic agents and offer alternatives to the use of NSAIDs. LZ can be a natural source of anti-inflammatory and anti-nociceptive agents.

Short communication: Identification of iron-binding peptides from whey protein hydrolysates using iron (III)-immobilized metal ion affinity chromatography and reversed phase-HPLC-tandem mass spectrometry.

Peptides with iron-binding capacity obtained by hydrolysis of whey protein with Alcalase (Novozymes, Araucaria, PR, Brazil), pancreatin, and Flavourzyme (Novozymes) were identified. Hydrolysates were subjected to iron (III)-immobilized metal ion affinity chromatography, and the bound peptides were sequenced by mass spectrometry. Regardless of the enzyme used, the domains f(42-59) and f(125-137) from ß-lactoglobulin enclosed most of identified peptides. This trend was less pronounced in the case of peptides derived from α-lactalbumin, with sequences deriving from diverse regions. Iron-bound peptides exhibited common structural characteristics, such as an abundance of Asp, Glu, and Pro, as revealed by mass spectrometry and AA analysis. In conclusion, this characterization of iron-binding peptides helps clarify the relationship between peptide structure and iron-chelating activity and supports the promising role of whey protein hydrolysates as functional ingredients in iron supplementation treatments.

Quantitative determination of active Bowman-Birk isoinhibitors, IBB1 and IBBD2, in commercial soymilks.

Naturally-occurring serine protease inhibitors of the Bowman-Birk family exert their potential chemopreventive and/or therapeutic properties via protease inhibition. In this study, we have quantified the amounts of active BBI isoinhibitors, IBB1 and IBBD2, in six commercial soymilks. By using cation exchange chromatography, the BBI isoinhibitors were isolated and their specific trypsin inhibitory activity was used to estimate their amounts in soymilk samples. IBB1 and IBBD2 concentrations ranged from 0.44 to 5.20 and 0.27 to 4.60 mg/100ml of soymilk, respectively; total BBI, considered as the sum of both isoinhibitors, ranged from 0.60 to 9.07 mg/100ml of soymilk. These data show that physiologically relevant amounts of active BBI are present in commercial soymilk and may exert potential health-promoting effects.

Acute and repeated dose (28 days) oral safety studies of ALIBIRD in rats.

ALIBIRD, a test substance composed of oligosaccharides derived from lactulose, a hydrolysate of a whey protein concentrate, and a supercritical extract of rosemary (1:0.5:0.05), was prepared in the laboratory and evaluated for its safety as a multifunctional food additive. In oral toxicity studies (acute and 28 days repeated dose) using Wistar rats, ALIBIRD was administered in a single oral gavage dose of 2,000 mg/kg of body weight and resulted in no adverse events or mortality; a daily dose of 2,000 mg/kg of body weight for 28 days by gavage also resulted in no adverse effects or mortality. No abnormal clinical signs, behavioral changes, body weight changes, or changes in food and water consumption occurred in either study. There were no changes in hematological and serum chemistry values, organ weights, or gross or histological characteristics. Based on test results, it is concluded that ALIBIRD is well tolerated in rats at an acute and subchronic (28 days) dose of 2,000 mg/kg of body weight.