Hypobaric Packaging Prolongs the Shelf Life of Refrigerated Black Truffles (Tuber melanosporum)

Abstract

Black truffle (Tuber melanosporum Vitt.) is a fine agro-food product known for its unique aroma and very limited shelf life (maximum of 5–7 days, room temperature). Hypobaric packaging at 30 kPa, a mix of 1% O2/99% N2, and 40% CO2/60% N2 were studied to prolong the shelf life of black truffle at 4 °C in sealed polypropylene vessels, compared to normal atmosphere. Epiphytic microbial population, firmness, weight loss, CO2 formation, and sensory properties were monitored weekly up to 35 days of storage and were related to the volatile profile. Principal components analysis revealed good correlation between the storage time and the decrease of firmness, and the increase of the microbial count and CO2 production. Only truffles stored under hypobaric conditions showed an acceptable quality after 14 days storage. Hypobaric packaging is a cheap strategy to prevent the swelling of vessels caused by respiration and can reduce the deviation from the high-quality level of the fresh product from one to at least two weeks.

Comparative evaluation of encapsulation using β‐cyclodextrin versus freeze‐drying for better retention and stabilizing of black Périgord truffle (Tuber melanosporum) aroma

“…The decrease of 1‐octen‐3‐ol after 90 days (Table 4) is most likely due to truffle degradation, which was also supported by Savini et al. (2020). Another study investigating the volatile changes in T. magnatum under accelerated storage at 23°C reported that methional did not significantly reduce with storage time (Niimi et al., 2021), which is contradictory to our observation (Table 4).…”

“…A previous study by Savini et al. (2020) reported an increase in ethyl‐3‐methylbutanoate throughout 35 days of refrigerator storage under different packaging conditions, and this phenomenon was related to the decay of fresh black truffles. The decrease of 1‐octen‐3‐ol after 90 days (Table 4) is most likely due to truffle degradation, which was also supported by Savini et al.…”

“…Another study investigating the volatile changes in T. magnatum under accelerated storage at 23°C reported that methional did not significantly reduce with storage time (Niimi et al., 2021), which is contradictory to our observation (Table 4). The contradictory results suggest that not all volatiles show similar changing patterns across similar studies, and the unclear trend in the volatile changes could be due to the natural variation among truffles and the complexity and changes of the truffle‐bacteria interactions under different storage conditions (Niimi et al., 2021; Savini et al., 2020). Niimi et al.’s (2021) study was based on white truffles from the Marche Region (central Italy), Hungary, and Croatia, and Savini et al.’s (2020) study was based on black truffles from the Abruzzo region (southern Italy), whereas we used black truffles harvested from western Australia in the present study.…”

“…The contradictory results suggest that not all volatiles show similar changing patterns across similar studies, and the unclear trend in the volatile changes could be due to the natural variation among truffles and the complexity and changes of the truffle‐bacteria interactions under different storage conditions (Niimi et al., 2021; Savini et al., 2020). Niimi et al.’s (2021) study was based on white truffles from the Marche Region (central Italy), Hungary, and Croatia, and Savini et al.’s (2020) study was based on black truffles from the Abruzzo region (southern Italy), whereas we used black truffles harvested from western Australia in the present study. It can be expected that in addition to the natural truffle to truffle variability, different growing regions will host different bacteria that can lead to differences in interactions with the truffles, leading to differences in the volatile profile changes, as reported by previous studies (Splivallo et al., 2015; Strojnik et al., 2020; Vahdatzadeh et al., 2015).…”

An Overview on Truffle Aroma and Main Volatile Compounds

“…Regarding the industry, another critical factor affecting truffle aroma is the preservation method used. Various processing and preservation techniques are typically used in the industry to protect aroma and help prolong their shelf life after harvest such as freeze-drying [ 56 , 57 ], refrigeration [ 58 ], irradiation [ 59 ], modified atmosphere packaging (MAP) with microperforated films [ 60 ], and Treatment combination (MAP, electron-beam irradiation, refrigeration) [ 61 , 62 , 63 ]. With the recent progress in food technology, more innovative ways are expected to preserve truffles whilst maintaining their sensory and biochemical properties.…”