Laurujisawat Patharapim, Dumrongchai Thatchawan, Rodklongtan Akkaratch, Chitprasert Pakamon
Technological Innovation of Probiotics and Plant Extracts for Functional Food Special Research Unit, Department of Biotechnology, Faculty of Agro-Industry, Kasetsart University, Bangkok, Thailand.
J Food Sci. 2025 May;90(5):e70257. doi: 10.1111/1750-3841.70257.
Probiotics face significant challenges during processing, storage, and gastrointestinal transit, leading to reduced viability and diminished health benefits in functional foods. This study investigated the effects of genipin crosslinking (2.5, 5, and 10 mM) on the structural and functional properties of whey protein isolate (WPI) as an encapsulant for Limosilactobacillus reuteri KUB-AC5 in probiotic-fortified cereal instant drinks. Fourier transform infrared spectroscopy (FTIR) confirmed covalent bonding between genipin and WPI, forming a reinforced protein matrix with reduced surface hydrophobicity, increased surface tension, and enhanced turbidity. Differential scanning calorimetry (DSC) further demonstrated that crosslinking initially improved thermal stability, with WPI-2.5G exhibiting the highest denaturation temperature (78.97°C), and enthalpy values (0.54 J/g), before decreasing at higher genipin concentrations due to potential protein aggregation. WPI-2.5G significantly improved probiotic survival after spray drying (8.13%), with flow cytometry confirming a higher proportion of intact cells and fewer injured cells, indicating enhanced protective functionality. After 4 months of storage at 4°C and 25°C, WPI-2.5G maintained superior probiotic viability, 2.69 × 10 CFU/serving (12.44% survival) and 3.47 × 10⁶ CFU/serving (0.02% survival), respectively, compared to other formulations. Furthermore, WPI-2.5G exhibited the highest survival rates after thermal reconstitution (2.98 × 10⁸ CFU/serving) and dynamic gastrointestinal digestion (5.69 × 10⁸ CFU/serving), exceeding the recommended threshold for probiotic efficacy. These findings demonstrate that genipin crosslinking, particularly at 2.5 mM, offers a promising strategy for enhancing probiotic viability and developing heat-stable, nondairy functional beverages.
益生菌在加工、储存和胃肠道转运过程中面临重大挑战，导致其在功能性食品中的活力降低，健康益处减少。本研究调查了京尼平交联（2.5、5和10 mM）对乳清分离蛋白（WPI）结构和功能特性的影响，WPI作为罗伊氏乳杆菌KUB-AC5的包封剂用于益生菌强化谷物速溶饮料。傅里叶变换红外光谱（FTIR）证实了京尼平和WPI之间的共价键合，形成了一种强化的蛋白质基质，其表面疏水性降低、表面张力增加且浊度增强。差示扫描量热法（DSC）进一步表明，交联最初提高了热稳定性，WPI-2.5G表现出最高的变性温度（78.97°C）和焓值（0.54 J/g），但在较高京尼平浓度下由于潜在的蛋白质聚集而降低。WPI-2.5G显著提高了喷雾干燥后益生菌的存活率（8.13%），流式细胞术证实完整细胞比例更高，受损细胞更少，表明其保护功能增强。在4°C和25°C储存4个月后，与其他配方相比，WPI-2.5G分别保持了优异的益生菌活力，即每份2.69×10⁷ CFU（存活率12.44%）和每份3.47×10⁶ CFU（存活率0.02%）。此外，WPI-2.5G在热复溶（每份2.98×10⁸ CFU）和动态胃肠道消化（每份5.69×10⁸ CFU）后表现出最高的存活率，超过了益生菌功效的推荐阈值。这些发现表明，京尼平交联，特别是在2.5 mM时，为提高益生菌活力以及开发热稳定的非乳制品功能性饮料提供了一种有前景的策略。
