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Pecan shell is a source of dietary fiber and phytochemicals, both necessary in the human diet. Therefore, pecan shell powder could be used as a supplement in the preparation of food products. The present study evaluated the effect of addition of 5, 10 and 15% (w/w) pecan shell powder, non-extruded (PSN) or extruded (PSE), in the physical properties of bread and wheat tortillas. Breads and tortillas produced with the higher substitution level that did not detriment significantly their physical properties (5% in breads and 10% in tortillas) were characterized in terms of chemical composition, total phenolic content (TPC), radical scavenging activity (RSA) and in vitro viability of human-derived liver cancer cells. Breads and tortillas produced with PSE (5% and 10%, respectively) presented the highest total dietary fiber content, TPC and RSA. In addition, extracts obtained from these same treatments, reduced the viability of hepatic cancer cells up to 53%. Sensory analysis of breads and tortillas supplemented with PSN or PSE showed adequate overall acceptability by consumers. Results obtained in the present study support that the pecan shell powder can be used as functional ingredient in bakery products especially when pretreated by extrusion., Peer Reviewed, Postprint (author's final draft)

Few studies had demonstrated the interaction of phlorotannins and polysaccharides from algae on microbial diversity and growth of probiotic bacteria on the early stages of colonic fermentation. Silvetia compresssa hydroethanolic extract rich in phlorotannins and its isolated polysaccharides fraction enabled the proliferation of Bifidobacterium and Lactobacillus and increased total short-chain fatty acids synthesis compared to a negative control. Eckstolonol, dieckol and acacetin derivative in hydroethanolic extract were depleted after eight hours of in vitro colonic fermentation. After a 48 h fermentation, hydroethanolic extract showed high levels of acetic (104.82 µmol g− 1 wet feces) and propionic acids (78.58 µmol g− 1 wet feces), as well as an increase in Bifidobacterium (log10 6.77 CFU g− 1 wet feces) and Lactobacillus (log10 4.25 CFU g− 1 wet feces) growth. These results showed no significant difference with inulin (p > 0.05), suggesting the potential of Silvetia compresssa hydroethanolic extract to improve human gut microbiota.

Purpose Solid-state fermentation (SSF) has been highlighted as an alternative to obtain valuable compounds using agro-industrial wastes as a substrate. The present study evaluated the impact of extrusion combined with SSF on the production of phenolic compounds and their antioxidant activity using pecan nut shell (PWS) as a substrate. Design/methodology/approach PWS and extruded pecan nut shell (PWSE) were fermented for 120 h at 30°C using Aspergillus oryzae (A. oryzae). Samples were withdrawn from incubator at 6 h, 12 h and then every 12 h until 120 h fermentation. PWS and PWSE samples were extracted. The total phenolic content (TPC) and radical scavenging activity (RSA) extracts were characterized from the resulting extracts. Findings The use of PWSE yielded higher A. oryzae biomass and at a higher rate after 120 h of fermentation (PWS 75.74% vs PWSE 87.50%). In general, the TPC and the RSA increased with fermentation time. However, the PWSE yielded significantly higher (p < 0.05) TPC and RSA values after SSF in comparison to the nonextruded PWS. Condensed tannins showed different trends depending on the fermented substrate. Overall, results showed that the extrusion pretreatment joint with the SSF represents a good alternative to raise the phenolic content and antiradical activity of lignocellulosic materials such as PWSs. Originality/value This study offers valuable information that may be used by the pecan walnut industry to valorize the shell coproduct as a substrate to produce functional ingredients or fungal enzymes., Peer Reviewed, Postprint (updated version)

The pecan (Carya illinoinensis) nut shell is an important byproduct of the food processing industry that has not been previously explored as an antioxidant compound. This work aims to study the effect of the extrusion temperature and screw speed on the moisture content, water and oil absorption index, water solubility index, color, phenolic compounds, condensed tannin compounds, and antioxidant activity of pecan nut shell extrudates. Extrusion variables were adjusted using a response surface methodology. Extrusion, performed at 70 °C and 150 rpm, almost doubled the concentration of polyphenols in the non-extruded shell and significantly increased radical scavenging activity. Compounds in extrudates, performed at 70 °C and 150 rpm, were quantified by high-performance liquid chromatography (HPLC) with a diode-array detector (DAD) and identified by liquid chromatography coupled with time-of-flight mass spectrometry (LC-MSD-TOF). Extrusion significantly increased most phenolic acid compounds, including gallic acid, ellagic acid pentose, ellagic acid, dimethyl ellagic acid rhamnoside, and dimethyl ellagic acid. The soluble fiber in extrudates was more than three-fold higher than in the control. Therefore, extrusion at 70 °C and 150 rpm increased the concentration of phenolic compounds, antioxidant activity, and total dietary and soluble fiber. Our findings support the notion that extruded pecan nut shell can be used in clean-label products and improve their nutraceutical value., Peer Reviewed, Postprint (published version)