Texture and Color of Frozen Inner and Outer Cabbage Leaves among Maturity Types

Aug 26, 2026

Effects of leaf layers on the texture and color of frozen cabbage leaves were examined across four maturity types. Early and medium maturity showed no significant firmness difference between inner and outer leaves, while medium-late and late cultivars retained greater outer-leaf firmness after freezing. Firmness correlated positively with cell wall components and total soluble solids. Outer-leaf color chroma increased after blanching and freezing independent of cell wall traits, whereas inner-leaf color retention linked to cell wall composition, notably AIS and insoluble dietary fiber.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages10

Reading Time25 min

AccessFree to download

Summary

1. Introduction

Texture and Color of Frozen Inner and Outer Cabbage Leaves among Maturity Types Chotika VIRIYARATTANASAK*† Tomoko HASHIMOTO* Yu HORIUCHI* Yasumasa ANDO** Namiko NISHIDA** Yuji TAKEMURA* Nobuko FUKINO*** *Tokyo Innovation Center, Nissui Corporation (1-32-3 Nanakuni, Hachioji-shi, Tokyo, 192-0991) **Institute of Food Research, National Agriculture and Food Research Organization (2-1-12 Kannondai, Tsukuba, Ibaraki, 305-8642) ***Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization (360 Ano, Tsu, Mie, 514-2392) Summary The effects of leaf layers on the texture and color of frozen cabbage leaves were examined among four maturity types. In early- and medium-maturity cabbages, there was no significant difference in the firmness of frozen inner and outer leaves, while in medium-late and late cultivars, the outer leaves retained markedly greater firmness. Additionally, frozen leaf firmness exhibited a strong positive correlation with cell wall components and total soluble solids. In terms of color, outer leaves consistently showed increased color chroma after blanching and freezing, irrespective of maturity type and without any clear association with cell wall components or total soluble solids. In contrast, color retention in frozen inner leaves was closely associated with cell wall components, particularly the levels of alcohol-insoluble solids and insoluble dietary fiber, showing decreased color chroma in early types. These results demonstrate that although cell wall integrity plays a pivotal role in preserving texture, color changes in frozen cabbage leaves cannot be explained by structural damage alone, suggesting a role for intrinsic factors such as initial pigment composition. Our findings suggest that selection of cultivar and plant segments are crucial determinants of frozen vegetable quality. Keywords: Cabbage, Leaf layer, Maturity type, Freezing, Firmness, Color 1. Introduction Improvement in preservation technology allows today’s frozen food products to maintain quality levels comparable to their original state. Nonetheless, vegetables remain especially vulnerable to quality deterioration, most notably texture softening and color degradation. Strategies to address these challenges now extend beyond technological improvement in processing to encompass the selection of appropriate cultivars, optimization of preharvest practices as well as detailed investigation into the structural and biochemical mechanisms that govern quality attributes during freezing 1-5) . In terms of texture, the firmness of frozen vegetables is primarily determined by the integrity of cell walls and their ability to resist damage due to ice crystal formation and growth. Cell wall integrity, as experimental evidence indicates, is predominantly governed by cell wall components and is strongly influenced by species and preharvest conditions 1-5) . For instance, the approximately 2.5-fold greater firmness of frozen cabbage leaves from late-maturing cultivars compared with early-maturing ones was resulted from their higher contents of total pectin, total cell wall materials (alcohol-insoluble solids, AIS), insoluble dietary fiber (IDF), and total soluble solids (TSS) 1) . By contrast, the firmness of frozen broccoli is reported to be governed predominantly by the growing season, rather than by maturity type3) . The temperature at harvest has been reported to modify the pectin composition of broccoli, particularly the proportion of water-soluble pectin, thereby influencing the ability of the cell wall to resist freezing-induced damage3-4) . With respect to color, under certain pre-freezing and storage conditions, freezing has been reported to successfully preserve or even enhance pigment stability relative to fresh counterparts6-7) . However, many vegetable species exhibit diminished color intensity or accelerated discoloration during freezing and subsequent storage7-8) . The severity of

FAQs

How did maturity type affect the firmness of frozen inner versus outer cabbage leaves?

Early- and medium-maturity cabbages showed no significant firmness difference between inner and outer leaves. Medium-late and late cultivars retained markedly greater firmness in the outer leaves.

What relationship was found between frozen leaf firmness and cell wall composition?

Frozen leaf firmness showed a strong positive correlation with cell wall components and total soluble solids.

Why do color changes differ between outer and inner frozen cabbage leaves?

Outer leaves consistently exhibited increased color chroma after blanching and freezing without a clear link to cell wall components or total soluble solids. Inner leaves showed color retention closely associated with cell wall components, with early types showing decreased color chroma.

Aug 26, 2026

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