Valorization of pistachio industrial waste: Simultaneous recovery of pectin and phenolics, and their application in low-phenylalanine cookies for phenylketonuria

Milad Kazemi; Sahar Aboutalebzadeh; Seyede Parastoo Mojaverian; Sara Amiri Samani; Fatemeh Kouhsari; Sepideh PourvatanDoust; Atiyeh Salimi; Mohamad Savarolyia; Amin Najafi; Seyed Saeid Hosseini; Faramarz Khodaiyan

doi:10.1016/j.ijbiomac.2023.126086

Valorization of pistachio industrial waste: Simultaneous recovery of pectin and phenolics, and their application in low-phenylalanine cookies for phenylketonuria

Int J Biol Macromol. 2023 Sep 30:249:126086. doi: 10.1016/j.ijbiomac.2023.126086. Epub 2023 Jul 31.

Affiliations

¹ Bioprocessing and Biodetection Laboratory, Department of Food Science and Engineering, University of Tehran, Karaj, Iran.
² Department of Food Science and Technology, Faculty of Agricultural Engineering, Agricultural Science and Natural Resources of Sari University, Mazandaran, Iran.
³ Department of Food Science and Technology, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran.
⁴ Department of Food Science, Engineering and Technology, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
⁵ Department of Food Science and Technology, Science and Research Branch, Islamic Azad University, Tehran, Iran.
⁶ Bioprocessing and Biodetection Laboratory, Department of Food Science and Engineering, University of Tehran, Karaj, Iran. Electronic address: khodaiyan@ut.ac.ir.

PMID: 37532194
DOI: 10.1016/j.ijbiomac.2023.126086

Abstract

This study introduces a sustainable approach to simultaneously produce pectin and phenolic compounds from pistachio industrial waste and applies them in the formulation of low-phenylalanine cookies. The co-optimization process was performed using the microwave-assisted technique and a Box-Behnken design, considering four variables and two responses: pectin yield and total phenolic content (TPC). The co-optimized condition (microwave power of 700 W, irradiation time of 210 s, pH level of 1.02, and LSR of 20 mL/g) resulted in a pectin yield of 15.85 % and a TPC of 10.12 %. The pectin obtained under co-optimized condition was evaluated for its physicochemical, structural, and thermal properties and the phenolic extract for its antiradical activity. Characterization of the pectin sample revealed a high degree of esterification (44.21 %) and a galacturonic acid-rich composition (69.55 %). The average molecular weight of the pectin was determined to be 640.236 kDa. FTIR and ¹H NMR spectroscopies confirmed the structure of pectin, with an amorphous nature and high thermal stability observed through XRD and DSC analysis. Additionally, the extract exhibited significant antiradical activity comparable to butylated hydroxyanisole and ascorbic acid. The isolated ingredients were used to formulate low-protein, low-phenylalanine cookies for phenylketonuria patients. The addition of 0.5 % pectin and 1 mL/g extract led to increased moisture content (from 9.05 to 12.89 %) and specific volume (from 7.28 to 9.90 mL/g), decreased hardness (from 19.44 to 10.39 N × 10²), and improved antioxidant properties (from 5.15 % to 44.60 % inhibition) of the cookies. Importantly, there was no significant increase observed in the phenylalanine content of the samples with pectin and extract addition. Furthermore, sensory evaluation scores demonstrated significantly higher scores for taste, odor, texture, and overall acceptability in cookies enriched with 0.5 % pectin and 1 mL/g extract, with scores of 4.53, 3.93, 4.40, and 4.60, respectively.

Keywords: Low-phenylalanine cookies; Pistachio waste valorization; Valuable ingredient recovery.

MeSH terms

Fruit / chemistry
Humans
Industrial Waste / analysis
Pectins / chemistry
Phenols / analysis
Phenylketonurias*
Pistacia*

Substances

Pectins
Industrial Waste
Phenols