Classification of Browning on Intact Table Grape Bunches Using Near-Infrared Spectroscopy Coupled With Partial Least Squares-Discriminant Analysis and Artificial Neural Networks

Abstract

Table grape browning is a complex physiological disorder that occurs during cold storage. There is a need to investigate novel and innovative ways to manage the problem that hampers the progressive and sustainable growth of table grape industries. Given the complex nature of the browning phenomenon, techniques such as near-infrared (NIR) spectroscopy can be utilized for the non-destructive classification of different browning phenotypes. In this study, NIR coupled with partial least squares discriminant analysis (PLS-DA) and artificial neural networks (ANN) were used to classify bunches as either clear or as having chocolate browning and friction browning based on the spectra obtained from intact ‘Regal Seedless’ table grape bunches that were cold-stored over different periods. Friction browning appears as circular spots close to the pedicel area that are formed when table grape berries move against each other, and chocolate browning appears as discoloration, which originates mostly from the stylar-end of the berry, although the whole berry may appear brown in severe instances. The evaluation of the models constructed using PLS-DA was done using the classification error rate (CER), specificity, and sensitivity and for the models constructed using ANN, the kappa score was used. The CER for chocolate browning (25%) was better than that of friction browning (46%) for weeks 3 and 4 for both class 0 (absence of browning) and class 1 (presence of browning). Both the specificity and sensitivity of class 0 and class 1 for friction browning were not as good as that of chocolate browning. With ANN, the kappa score was tested to classify table grape bunches as clear or having chocolate browning or friction browning and showed that chocolate browning could be classified with a strong agreement during weeks 3 and 4 and weeks 5 and 6 and that friction browning could be classified with a moderate agreement during weeks 3 and 4. These results open up new possibilities for the development of quality checks of packed table grape bunches before export. This has a significant impact on the table grape industry for it will now be possible to evaluate bunches non-destructively during packaging to determine the possibility of these browning types being present when reaching the export market.

The Diversity in Grapes of Vitis labrusca Grown in Bolu (Türkiye) Assessed by Multivariate Approaches

“…One of the most important aspects when distinguishing grape types is the heterogeneous ripening behavior. Not all biological processes occur simultaneously in plant organs, and berries within the same cluster may not mature uniformly [40]. Some of the circumstances that can produce uneven maturation are the location of the vine in the vineyard, and the position of the cluster on the vine [41].…”

Optical Property Mapping of Apples and the Relationship With Quality Properties

“…Quality evaluation on intact apple fruit, which is the key step in the process of grading and sorting, is gaining tremendous interest and attention in the field of non-destructive inspection. In the past decades, visible and near-infrared (Vis/NIR) spectroscopy has been widely developed and adopted for quality assessment of plant and food products ( Zhao et al, 2020 ; Daniels et al, 2021 ; Li and Zhang, 2021 ; van Wyngaard et al, 2021 ; Wan et al, 2021 ), thanks to its rapid and non-invasive character. A large number of statistical models based on Vis/NIR spectroscopy have been built for predicting apple quality properties, such as firmness, crispness, soluble solid content (SSC), and acidity ( Gao et al, 2016 ; Fan et al, 2020 ; Huang et al, 2020 ; Tian et al, 2020 ).…”

Occurrence of Skin Browning according to Cluster Weight and the Gibberellic Acid (GA3) Concentration in ‘Shine Muscat’ Grapes

“…갈변에 관한 연구로는 저장 조건에 따른 'Fuji' 사과의 과육 갈변 (Lee and Choi, 1997), 동양배 'Niitaka' 품 종의 과피 얼룩 및 과심 갈변 장해에 대한 연구 (Whang et al, 2003), 근적외선을 사용하여 비파괴적 방법으로 내부 갈변 사과 를 판별하는 연구 (Kim and Lim, 2021) 등이 수행되었다. 포도에서는 저장 중 과경의 갈변 (Hamie et al, 2022;Unal et al, 2022), 저장 중 충격 혹은 진균 감염으로 인한 내부 갈변 (Daniels et al, 2021) 등 주로 저장과 관련된 연구가 진행되었으며, 'Shine Muscat' 이전에는 국내에서는 대부분 흑포도 품종이 재배되어 과피의 갈변에 관한 연구는 거의 진행된 바가 없다. 과피 에관해서는 적포도인 'Crimson Seedless' 포도에서 착색과 포도의 품질 향상을 위해 기존에 처리되던 에테폰와 그 대체제로 써 brassionlide 처리와 환상박피를 통한 비교 연구 (Belal et al, 2022)나 청포도인 'Shine Muscat' 포도에서 수확기 포도의 숙 기별 과방의 색 비교를 통한 color chart를 만드는 연구 (Kim et al, 2019) 등 진행되었지만 갈변 연구와는 거리가 있다.…”