Elsevier

Food Chemistry

Volume 190, 1 January 2016, Pages 643-656
Food Chemistry

HS-GC–MS volatile compounds recovered in freshly pressed ‘Wonderful’ cultivar and commercial pomegranate juices

https://doi.org/10.1016/j.foodchem.2015.06.005Get rights and content

Highlights

  • Solid phase microextraction isolated 36 compounds in whole pressed ‘Wonderful’ juice.

  • Eighteen of 21 consensus compounds were isolated from whole-pressed fruit.

  • Solid phase microextraction isolated 41 compounds in arils-only ‘Wonderful’ juice.

  • Seventeen compounds considered as consensus were isolated from arils-only juices.

  • Vast dissimilarity existed in compounds recovered in commercial versus fresh juices.

Abstract

Consumption and production of superfruits has been increasing. Highly colored fruits often have bitter and astringent components that may make them undesirable, especially when processed. Many pomegranate volatile reports involved commercial samples, complicated isolation methods, or blending and concentrating that were from arils only, cultivars other than ‘Wonderful’, or mixed cultivars. Solid phase microextraction (SPME), polydimethylsiloxane stir bar sorptive extraction, and Tenax adsorption were performed with freshly pressed ‘Wonderful’ juices, commercial juices and concentrates. Using SPME, 36 compounds were isolated in whole pressed ‘Wonderful’ juices, including 18 of the 21 consensus compounds. In arils-only juices, 41 compounds were isolated by SPME, including 17 of the consensus volatiles. Dramatic variation existed in volatiles recovered in commercial juices and isolation of consensus compounds was sporadic. This article and summary of the literature serves to possibly deliver an improved volatile data set via a rapid method for fresh and partially processed (pressed) pomegranates.

Introduction

Heightened consumer awareness of the health benefits of consuming phytonutrient-rich fruits and keen marketing have created the demand for, and availability of juices and functional beverages prepared from them. The juice/beverage and functional food industry has rapidly advanced several pomegranate containing products driven by this consumer awareness of “superfruits.” Superfruits have become mainstream within the juice and functional beverage category because they are an easy mechanism by which to deliver proven nutritional benefit (e.g., vitamins, fatty acids, and minerals) and antioxidants into the diet. The anti-inflammatory, anti-carcinogenic, antimicrobial and anti-mutagenic characteristics of pomegranate (Punica granatum) enriched diets, that help protect the brain, cardiovascular and central nervous system, and reduce type 2 diabetes etc. [see references within reviews (Basu and Penugonda, 2009, Johanningsmeier and Harris, 2011)] have led to a remarkable surge in production and consumption of pomegranate products.

POMWonderful, LLC, the company who started the pomegranate juice niche in the U.S., increased sales from $12 million in 2003 to $91 million in 2006 (Cline, 2008). In 2011, California had an estimated 30,000 acres of pomegranates (Geisler, 2012) and in just Kern County, CA, there was an estimated $115 million farm gate value (Pollock, 2011). However, highly colored dark-pigmented fruits and berries offering potential health benefits often have several constituents that can make them bitter or astringent (Lawless, Threlfall, Meullenet, & Howard, 2013). Therefore, the long-term increased demand and full potential use of superfruits and their expanding markets may not be sustained if flavor changes and/or possible off-flavors associated with processing, bitterness and astringency are not studied, understood, and ultimately resolved. For example, a product development survey indicated that superfruit beverages may have already given way to traditional fruit flavors, and fusion/coupled flavors (Sloan, 2011). Although anecdotally, world-wide current pomegranate market offerings do not seem to support this supposition. Juices and functional beverages containing polyphenolic-rich fruits and vegetables are successfully being marketed en masse due to their presumed and likely in vivo health benefits. Subsequently, a plausible research and development effort for currently produced superfruits and 100% juices might be to improve the existing consumer quality attributes, while maintaining high phytonutrient status.

Many pomegranate volatile reports involved commercial samples and/or isolation methods that were either excessively lengthy and laborious, often employing solvents, or they potentially oxidized the initial juice during extraction by blending or concentrating, while other volatile characterizations have emanated from arils only, cultivars other than ‘Wonderful’ or mixed cultivar juices (Cadwallader et al., 2010, Caleb et al., 2013, Calin-Sanchez et al., 2011, Fawole and Opara, 2014, Melgarejo et al., 2011, Nuncio-Jauregui et al., 2014, Vazquez-Araujo et al., 2011a, Vazquez-Araujo et al., 2011b). Some reported methods have not removed possible green grassy (aldehydic) notes or possibly preserved them (by enzyme inhibition) in subsequent isolation steps (Cadwallader et al., 2010, Calin-Sanchez et al., 2011, Melgarejo et al., 2011, Vazquez-Araujo et al., 2011a, Vazquez-Araujo et al., 2011b). Other reports involving hand extracted and pressed ‘Wonderful’, ‘Mollar de Elche’ and ‘C25’ arils (Spanish line) are likely to have resulted in less oxidation, even though laborious solvent extractions or arils-only juices were used (Carbonell-Barrachina et al., 2012, Mayuoni-Kirshinbaum et al., 2013, Mayuoni-Kirshinbaum et al., 2012). Consequently, several volatile reports have not treated pomegranate juices in an extraction- and commercial-like manner common in the U.S., involving pressing whole fruit (as opposed to arils) without maceration, filtration, concentration and pasteurization.

In this report, the goal was to investigate the volatile compounds in freshly pressed, partially processed, not-from-concentrate (NFC), 100% pure ‘Wonderful’ pomegranates [the dominant U.S. and Israeli cultivar, also used worldwide for industrial purposes, (Holland, Hatib, & Bar-Ya’akov, 2009)]. For evaluation, whole-pressed fruit juice was pasteurized and concentrated then reconstituted to mimic U.S. commercial product. For comparison-sake, volatiles were also evaluated in ‘Wonderful’ arils only juice and commercial U.S. concentrates and juices. Relatively rapid qualitative, non-invasive extraction methods were used to outline a suite of pomegranate volatiles, in advance of future reports illustrating flavor/sensory effects encountered through industrial-like pasteurization and storage, in NFC ‘Wonderful’ juices.

Section snippets

‘Wonderful’ plant material

Commercially ripe pomegranate (P. granatum ‘Wonderful’) fruit was harvested several times in two years, early (lots A–E) and late (lot F) season, sorted, graded, waxed, and shipped immediately, or stored under proprietary controlled atmospheres (CA) at 8 °C (Paramount Farms, Del Rey, CA, U.S.). Fruit were repacked into, or already stored in commercial boxes containing a shelf-life extending polymeric sack (Xtend Fresh Product Packaging Technology, StePac L.A. Ltd. Encinitas, CA, U.S.). A

Volatile recovery using various extraction techniques in pomegranate juices

Modified HS SPME GC–MS volatile methods have been routinely used for several years in fruit appraisals in our laboratory, along with the highly analogous SBSE technique (Amaro et al., 2012, Beaulieu and Grimm, 2001). However, as several less polar and solvent-extracted volatiles were previously reported in pomegranate (Cadwallader et al., 2010, Raisi et al., 2008, Yamagami and Umano, 2000), a few volatile extraction techniques (SPME, SBSE and Tenax) were investigated, attempting to rapidly

Conclusion

In our study, especially using concentrates and reconstituted juices, some typical and oftentimes considered important aroma attributes appeared to be absent in ‘Wonderful’. Whereas, other compounds, assuming above threshold, might need to be added to the consensus listing. Herein, we report several similar compounds previously isolated in ‘Wonderful’ and ‘Mollar de Elche’, and likewise expand the possible suite of important ‘Wonderful’ compounds (Table 2, Table 3). However, this presumes that

References (40)

  • J.C. Beaulieu et al.

    Identification of volatile compounds in cantaloupe at various developmental stages using solid phase microextraction

    Journal of Agricultural and Food Chemistry

    (2001)
  • J.C. Beaulieu et al.

    Characterization and semiquantitative analysis of volatiles in seedless watermelon varieties using solid-phase microextraction

    Journal of Agricultural and Food Chemistry

    (2006)
  • J.C. Beaulieu et al.

    Processing and enzymatic treatment effects on Louisiana grown fresh satsuma juice

    Journal of the American Society for Horticultural Science

    (2014)
  • K.R. Cadwallader et al.

    Aroma Components of Fresh and Stored Pomegranate (Punica granatum L.) Juice

  • A. Calin-Sanchez et al.

    Volatile composition and sensory quality of Spanish pomegranates (Punica granatum L.)

    Journal of the Science of Food and Agriculture

    (2011)
  • A.A. Carbonell-Barrachina et al.

    Potential of Spanish sour-sweet pomegranates (cultivar C25) for the juice industry

    Food Science and Technology International

    (2012)
  • H.S. Choi

    Volatile constituents of satsuma mandarins growing in Korea

    Flavour and Fragrance Journal

    (2004)
  • H. Cline

    Loquaci Ranch site of first mechanical pomegranate harvester demonstration

    Western Farm Press

    (2008)
  • O.A. Fawole et al.

    Physicomechanical, phytochemical, volatile compounds and free radical scavenging properties of eight pomegranate cultivars and classification by principal component and cluster analyses

    British Food Journal

    (2014)
  • FDA. (2014). CFR – Code of Federal Regulations Title 21; Food labeling; Specific Food Labeling Requirements....
  • Cited by (36)

    • Not-from-concentrate pilot plant ‘Wonderful’ cultivar pomegranate juice changes: Quality

      2020, Food Chemistry
      Citation Excerpt :

      Flow rate, inlet and outlet pressures were monitored, and Brix, anthocyanins and organic acids concentrations were utilized to test the < 5% threshold across the membrane in the BRO/BUF, in all runs. The above three NFC UF PJ were concentrated using a Büchi R-215 Rotavapor (Flawil, Switzerland) with a vacuum pulled to 72 mbar, as previously described (Beaulieu & Stein-Chisholm, 2016). These stored (−20 °C) concentrates (RConstSRRC) and three separate commercial ‘Wonderful’ cultivar concentrates (RConst#1) were reconstituted into 100% single strength juice, as per U.S. Code of Federal Regulation [CFR 101.30, Title 21, Part 101, (FDA, 2011)], at 16 Brix.

    View all citing articles on Scopus

    Disclaimer: Mention of a trademark or proprietary product is for identification only and does not imply a guarantee or warranty of the product by the U.S. Department of Agriculture. The U.S. Department of Agriculture prohibits discrimination in all its programs and activities on the basis of race, color, national origin, gender, religion, age, disability, political beliefs, sexual orientation, and marital or family status.

    View full text